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Department of Industrial Engineering and Management, R.V. College of Engineering, Bangalore 59.

Edition

2006

Dept. of Industrial Engineering & Management Laboratory Manual

Material Testing lab Manual

Department of Industrial Engineering and Management, R.V. College of Engineering, Bangalore 59.

Department of Industrial Engineering and Management

M T R LT ST GL B A E IA E IN AR.V. College of Engineering, Bangalore 59 MATERIALS TESTING LABORATORY SCHEME OF CONDUCT AND EVALUATION CLASS: III SEMESTER (New Scheme) YEAR: 2006 Sl. No 01 02 03 04 05 06 07 08 09 10 11 12 13 Expt. No. MT01 MT02 MT03 D01 MT04 MT05 MT06 D02 MT07 MT08 MT09 MT10 S01 S02 D03 Title CYCLE I Tension Test on Mild Steel Specimen Torsion Test on Mild Steel Specimen Impact Tests (IZOD and CHARPY) on Mild Steel Specimen Non-Destructive Tests Demonstration Rockwell hardness Test CYCLE II Wear Test Double Shear Test on Mild Steel Specimen Fatigue Test demonstration Compression Test on Mild Steel Specimen Brinell Hardness Test CYCLE III Vickers hardness Test Bending Test on wood Preparation of specimen for metallographic examination. Microstructure study of the Engineering materials identification Heat treatment of steel materials & study of their hardness using their Rock-well testing machine--Demonstration TEST TOTAL SUBJECT CODE: MEL37 A CLASS MARKS: 25 No. of Class 01 01 01 01 01 01 01 01 01 01 01 01 01 13 Class & Test Marks 20 20 20 20 10 20 20 20 10 20 10 10 50 250

KEY MT Materials Testing Expt. S Study Expt. D Demonstration Expt.

Material Testing lab Manual

Department of Industrial Engineering and Management, R.V. College of Engineering, Bangalore 59.

EVALUATION SCHEME: CLASS MARKS (Reduced to 25) Proposed by: D.Venugopal setty. Shobha N S = Class work total + Test Marks 10 Prepared by: H.M.Shadakshara Approved by Prof.K.S.Badarinarayana

SYLLABUS MATERIALS TESTING LABORATORY (Common to ME I IP I AU I IM I MA) Sub Code MEL37 A/MEL47 A IA Marks 25 Hrs/Week 03 Exam Hours 03 Total Hrs. 42 Exam Marks 50 PART-A 1. Preparation of specimen for metallographic examination of engineering materials and study the microstructure of plain carbon steel, tool steel, gray C.I, SG iron, Brass, Bronze. 2. Heat treatment: Annealing normalizing hardening and tempering of steel & to study their Rock-well hardness (Demonstration only) PART-B 3. Conduction of tensile, shear, compression, torsion and bending tests of a Mild Steel specimen using a Universal Testing Machine. 4. Conduction of Izod and Charpy tests on Mild Steel Specimen. 5. Experiment on Wear Study. 6. Brinell, Rockwell and Vicker's Hardness tests. 7; .Fatigue Test- (demonstration only). 8. Non-destructive test experiments - (demonstration only). (a). Ultrasonic flaw detector (b). Magnetic crack detector (c). Dye penetrant testing Scheme of Examination: ONE question from part -A (Identification only) ONE question from part -B Viva-Voce : : : 10 Marks 30 Marks 10 Marks

Material Testing lab Manual

Department of Industrial Engineering and Management, R.V. College of Engineering, Bangalore 59.

Material Testing lab Manual

Department of Industrial Engineering and Management, R.V. College of Engineering, Bangalore 59.

INTRODUCTION: Materials constitute an important component of the curriculum of every branch of engineering and applied science. For fabrication of machines, manufacture of parts, building of plants and structures, and carrying out processes, the choice of the material is critical. An awareness of materials available to the characteristic material properties & us are desirable for efficient problem solving, decision-making, and development of advanced materials and functioning of an engineer. The need for materials literacy of engineers and technologists is now recognized all over the world. It is clear that an engineer should keep the materials scenario in mind while designing a component or machine. Otherwise his design may become redundant. For the efficient design of engineering products, problem solving, decision making and the overall efficient functioning of an engineer, an awareness of available materials, there potentials and limitations, and an understanding of there properties and behaviour or desirable. Every engineering material is known by its set of properties. A variety of tests are conducted in the Material Testing Laboratory to evaluate & compare the mechanical properties of different materials. The Mechanical Properties are: 1. 2. 3. 4. 5. Stiffness Elastic Strength Yield Strength Ductility Malleability 6. Ultimate Tensile Strength 7. Fracture Strength 8. Stress 9. Strain 10. Toughness

These tests are classified into three categories: 1. Loading conditions Static tests - Tension, compression, Torsion, Bending, Shear Tests Dynamic testsImpact tests- Charpy Test, Izod Test Repeated loading - Fatigue test. High Temperature tests - Creep test 2. Hardness Tests Penetration Tests - Rockwell Hardness Test, Brinell Hardness Test, Vickers Hardness Test 3. Non- destructive Tests Visual Inspection Magnetic Particle inspection Magnetic crack detector Dye penetrate test Radiography Ultrasonic test X-Ray test.

Material Testing lab Manual

Department of Industrial Engineering and Management, R.V. College of Engineering, Bangalore 59.

EXPERIMENT No. MT01

TENSION TEST ON DUCTILE MATERIALAIM: - To determine the strength and several properties of ductile steel, to observe the behaviour of the material under load and to study the fracture and thus determine the following: 1. 2. Yield strength Tensile strength

3. Ductility i. Percentage elongation ii. Percentage reduction in area 4. Modulus of elasticity (Graphical Method) APPARATUS / INSTRUMENTS / EQUIPMENT USED: 1. Universal Testing machine 2. Extensometer 3. Vernier caliper 4. scale UNIVERSAL TESTING MACHINE

Equipment Description:UTM as name implies, are general purpose machines. They vary greatly in physical size, load capacity, versatility & sophistication. In its simplest form, a UTM system includes a load frame where the test is actually performed. The load frame must, of course, be rugged enough for the application. Some means of control over the load frame is necessary. This control can be as simple as hand wheel on a valve or as complex as a

Material Testing lab Manual

Department of Industrial Engineering and Management, R.V. College of Engineering, Bangalore 59.

computer to control the loading & unloading process and the rates at which these are done. Generally a recorder is used to record permanently the results of the tests. Grips or some other accessory are used to interphase between the sample being tested & the load frame itself. The action & use of the grips is often one of the most critical and least understood parts of the test. Each UTM is desired to have a maximum load capacity. Small units may have a load of few 100N or even less. The UTM can be used for: 1. Tensile test 2. Shearing test 3. Compression test 4. Bending test 5. Functions of i. Yield point ii. Elasticity Modulus, iii. Young's Modulus iv. Ultimate value v. Break value PROCEDURE:1. Determine the average cross-section of the given specimen. Scribe a line along the bar and with a centre punch lightly mark a 120 mm gauge length symmetrical with the length of the bar. 2. Firmly grip the upper end of the specimen in the fixed head of the testing machine using proper fixing devices or shackles. The specimen is placed such that the punch marks face the front of the machine 3. Firmly attach the extensometer to the specimen so that the axis coincides with that of the specimen. Adjust the testing machine and extensometer to read zero. Grip the lower end of the specimen taking care not to disturb the fixing of the extensometer. 4. Select suitable increments of load (between 200 and 500 kgs) to obtain at least 15 readings of strain within the proportional limit. Apply the load at a slow speed, taking simultaneous observations of load and strain without stopping the machine. The extensometer is used only till the yield point value is reached at which point the extensometer dial makes two complete revolutions. After this, the elongation is observed on the scale fixed to the machine frame. 5. Loading is continued till the failure of the specimen. Record the ultimate load and breaking load. 6. Remove the broken specimen from the machine and observe the failure characteristics. Measure the dimension of the smallest section. Hold the broken parts together and measure the gauge length. 7. Plot a stress-strain diagram and mark the following on the graph: a. Upper yield point b. Lower yield point

Material Testing lab Manual

Department of Industrial Engineering and Management, R.V. College of Engineering, Bangalore 59.

c. Breaking stress d. Ultimate stress

8. Calculate the slope of the graph (within the elastic limit), which is the Youngs modulus value of the given material. R.V. COLLEGE OF ENGINEERING, BANGALORE-560059 DEPARTMENT OF INDUSTRIAL ENGG. AND MANAGEMENT MATERIAL TESTING LABORATORY OBSERVATION / DATA SHEET Date: Lab : MT Lab Name: Class: III Sem USN: Expt.No:

Title of the Experiment: TENSION TEST OBSERVATIONS: Least count of extensometer =0.01mm Least count of Vernier caliper = 0.02mm DETAILS OF SPECIMEN: Material : Mild steel Total length of specimen (L) :330mm Length between shoulders (l) :133mm Gauge length (l1) :120mm Diameter at the ends (D) :19mm Diameter of reduced section (d) :14mm Diameter of ruptured section (d1) :8.5mm Gauge length after fracture (l2) :15.5mm SKETCH OF THE SPECIMEN:Shoulder

d

D

l1 l L

Material Testing lab Manual

Department of Industrial Engineering and Management, R.V. College of Engineering, Bangalore 59.

Contd.. Signature of the staff in charge R.V. COLLEGE OF ENGINEERING, BANGALORE-560059 DEPARTMENT OF INDUSTRIAL ENGG. AND MANAGEMENT MATERIAL TESTING LABORATORY OBSERVATION / DATA SHEET Date: Lab : MT Lab Name: Class: III Sem USN: Expt.No:

Title of the Experiment: TENSILE TEST EXPERIMENTAL READINGS: Extensometer Reading Sl. No 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Load (Kg) 500 1000 1500 2000 2500 3000 3500 4000 4500 5000 5500 6000 6500 7000 Left 3 6 7 10 11.5 13 15 17 19 20.5 22.5 Right 0 0 1 3 4.5 6 8 9.5 11 13 16.5 1.5 3 4.5 Scale reading (mm)

Remarks

Yield point

Material Testing lab Manual

Department of Industrial Engineering and Management, R.V. College of Engineering, Bangalore 59.

15 16 17 18 19 20

7500 8000 8500 8000 6500 6000

6.5 9.5 13 35 39.5 40

Ultimate point Breaking point

Signature of the staff in charge R.V. COLLEGE OF ENGINEERING, BANGALORE-560059 DEPARTMENT OF INDUSTRIAL ENGG. AND MANAGEMENT MATERIAL TESTING LABORATORY OBSERVATION / DATA SHEET Date: Lab : MT Lab Name: Class: III Sem USN: Expt.No:

Title of the Experiment: TENSILE TEST Tabulated results: Sl. Load Extensometer Reading No (mm) Left Right Average 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 4905 9810 14715 19620 24525 29430 34335 39240 44145 49050 53955 58860 63765 68670 73575 78480 0.03 0.06 0.07 0.1 0.115 0.13 0.15 0.17 0.19 0.205 0.205 0 0 0.01 0.03 0.045 0.06 0.08 0.095 0.11 0.13 0.165 0.015 0.03 0.04 0.065 0.08 0.095 0.115 0.1325 0.15 0.1675 0.195 1.5 3 4.5 6.5 9.5 Scale Reading (mm) Stress (N/mm2) 31.86 63.73 95.59 127.46 159.32 191.19 223.05 254.92 286.78 318.65 350.51 382.38 414.25 446.11 477.97 509.85 Strain Remarks

0.00013 0.00025 0.00033 0.00054 0.00067 0.00079 0.00096 0.00110 0.00125 0.00140 0.00163 0.0125 0.025 0.0375 0.0542 0.07916

Yield point

Material Testing lab Manual

Department of Industrial Engineering and Management, R.V. College of Engineering, Bangalore 59.

17 18 19 20 21 22

83385 78480 73575 68670 63765 58860

13 35 36 37.5 39.5 40

541.70 509.85 477.97 466.11 414.25 382.38

0.1083 0.2916 0.3083 0.3167 0.329 0.3334

Ultimate point

Breaking Point

Signature of the staff in charge Stress-Strain Diagram600 500 stress(N/mm2) 400 300 200 100 00. 00 0 0. 13 00 0 0. 33 00 0 0. 67 00 0 0. 96 00 1 0. 25 00 16 3 0. 02 0. 5 05 4 0. 2 10 8 0. 3 30 83 0. 32 9

strain

SPECIMEN CALCULATION: For Sl. No.3 1.Applied load , P = 1500 x 9.81 =14715 N 2.Area of cross section before fracture , A= d / 4 = x (14)2 /4 = 153.93 mm2 3.Area of cross section after fracture = d12 / 4 = x (8.5)2 /4 = 56.745 mm2 4.Applied stress = P / A = Load/ Initial area of cross section = 14715/153093 = 95.595 N/mm2 = 77.18 X106 N/m2

Material Testing lab Manual

Department of Industrial Engineering and Management, R.V. College of Engineering, Bangalore 59.

5. Strain = Change in length / Original length = 0.035/120= 0.000333 6. % Elongation = Change in gauge length X100 / Original gauge length = (L2 -L1 )X 100 / L1 = (155-120)X100/120 = 29.17% 7. % Reduction in area = (Original area Area after fracture)X100 / Original area = (153.93 56.745 )X100 / 153.93 = 63.135% 8.Yield strength = Load at yield point / Initial area of cross section = 5300*9.81/153.93 = 337.77 N/mm2 =3.377 X108 N/m2 9. Tensile strength = Maximum load / Initial area of cross section = 83385/153.93= 541.7 N/mm2 = 5.417 X108N/m2 10. Breaking strength = Load at break point / Initial area of cross section = 58860/153.93=382.382 N/mm2 =3.823 X108 N/m2 11.Modulus of elasticity (Graphical), E = Slope of Graph = 2.4 X1011N/m2 RESULT :Experimental results are as follows: Percentage elongation = 29.166% Percentage reduction in area = 63.135% Yield strength = 3.377 X108 N/m2 Tensile strength = 5.417 X108N/m2 Breaking strength = 3.823 X108 N/m2 Modulus of elasticity (Graphical), E = 2.4 X1011N/m2

Material Testing lab Manual

Department of Industrial Engineering and Management, R.V. College of Engineering, Bangalore 59.

EXPERIMENT No. MT02

TORSION TESTAIM: - To determine the behaviour of ductile steel when subjected to torsion, and obtain the following tensional properties: Modulus of rigidity Maximum Shear strength of the material APPARATUS/EQUIPMENT/INSTRUMENTS USED Torsion testing machine, Torsion Shackles, Vernier Calipers TORSION TESTING MACHINE

Equipment description: Torsion Testing Machine is designed for conducting Torsion and Twist on various metal wires, tubes, sheet materials. This Machine applies a torque on the specimen held in its chuck and measures the twist. Suitable for Torsion and Twist test on various metal rods and flats. Torque measured by pendulum dynamometer system. Geared motor to apply torque to specimen through gear box. Set of jaws to accommodate different size and diameter of test specimens provided.

Material Testing lab Manual

Department of Industrial Engineering and Management, R.V. College of Engineering, Bangalore 59.

R.V. COLLEGE OF ENGINEERING, BANGALORE-560059 DEPARTMENT OF INDUSTRIAL ENGG. AND MANAGEMENT MATERIAL TESTING LABORATORY OBSERVATION / DATA SHEET Date: Lab : MT Lab Name: Class: III Sem USN: Expt.No:

Title of the Experiment: TORSION TEST OBSERVATIONS: Least count of the Vernier caliper =0.01mm Least count of the Torque Indicator r=60Kg-cm Least count Twist Indicator =0.5 TORQUE AND TWIST READINGS: Sl.No. 1. 2. 3. 4. 5. 6. 7. TORQUE Kg-Cm (x 60) 0 3 12 14 15 16 17 Twist (Degrees) 1 10 20 30 40 50 60 70 2 0 0.25 0.75 1.00 1.25 1.25 1.25

Signature of the staff in charge

Material Testing lab Manual

Department of Industrial Engineering and Management, R.V. College of Engineering, Bangalore 59.

PROCEDURE:1. Measure the dimensions of the specimen using Vernier caliper 2. Fix the specimen between the shackles. The axis of the specimen should coincide with the axis of the shackles 3. Rotate the wheel very slowly to give a twist of 1=10 4. Note down the corresponding torque developed (kg-cm), T and the angle of twist, 2 from the indicators. 5. Increase the twist 1 in steps of 10 till the failure of the specimen. Note the corresponding values of 2 and T. 6. Calculate the effective twist, = 1 ~ 2 7. Calculate shear strength using formula, = T x R / J 8. Plot a graph between and . 9. Calculate rigidity modulus from the slope, G = Slope x L / R TABULATION: Sl No 1 2 3 4 5 6 Torque (division) 0 3 12 14 15 16600 500 400 300 200 100 00.1745 0.3447 0.5105 0.6807 0.8508 1.0254

Torque (N-m) 0 17.658 70.632 82.404 88.290 94.176

1

TWIST (Degree) = 1 ~ 2 2 0 0.025 0.75 1.00 1.25 1.25 10.00 19.75 29.25 39.00 48.75 58.75

TWIST, (radians) 0.1745 0.3447 0.5105 0.6807 0.8508 1.0254

Shear Stress, (x108N/m2) 0 89.93 359.72 419.68 449.66 479.63

10 20 30 40 50 60

Shear Stress (x10 8 N/m )

2

Twist (Radians)

Material Testing lab Manual

Department of Industrial Engineering and Management, R.V. College of Engineering, Bangalore 59.

SPECIMEN CALCULATION (for sl.no.2) 1. Torque division = 3 Torque (T) = 3x60 Kg- Cm T = 3x60x9.81/100 = 17.658 N m 2. Twist, = 1 ~ 2= 20 ~ 0.25 = 19.75 = 19.75 x /180 = 0.3447 radians 3. Diameter (D) = 10 mm, Polar moment of inertia, J = D4 / 32 = (10)4 / 32 = 981.75 mm4 = 981.75 x10-12 m4 4. Shear stress, = T x R /J = 17.658 x (5/1000)/ 981.75 X10-12 = 8.993 x107 N/m2 5. Maximum shear stress, max = 5.0961 x108 N/m2 6. 1. Modulus of rigidity or Polar Moment of Inertia, G = Slope x L / R N/m2 =(1.56x103x130)/5=4.056x109 N/m2 RESULTS: 1. Maximum shear stress 2. Modulus of rigidity = 5.0961 x108 N/m2 = 4.056 x 109 N/m2

Material Testing lab Manual

Department of Industrial Engineering and Management, R.V. College of Engineering, Bangalore 59.

EXPERIMENT No. MT03

IMPACT TEST IZOD AND CHARPYAIM:- To determine the relative impact resistance of a given specimen by conducting the IZOD and Charpy tests. APPARATUS / INSTRUMENTS / EQUIPMENT USED: Impact testing machine, Vernier caliper, Centerpiece or setting gauge, Allen key. IMPACT- TESTING MACHINE

Theory: Impact loading differs from quasi-static loading. In that a load is applied over a very short time instead of being introduced gradually at some constant rate. This causes significant changes in the observed material properties from those associated with normal static tests. In the case of impact loading the effects measured are of a dynamic nature, with vibration and possibly fracture being observed. The Notched Bar test, where specimens are subjected to axial, bending or torsion loads using specialized testing machines. The technique involves swinging a weight of W from a certain specified height h to strike the notched specimen, breaking it as it passes through, and arriving at a

Material Testing lab Manual

Department of Industrial Engineering and Management, R.V. College of Engineering, Bangalore 59.

height h', lower than the initial position of the pendulum. The energy expended in rupturing the specimen can be described using the equation U = W (h-h') Where, W= Weight h & h= Specified height

R.V. COLLEGE OF ENGINEERING, BANGALORE-560059 DEPARTMENT OF INDUSTRIAL ENGG. AND MANAGEMENT MATERIAL TESTING LABORATORY OBSERVATION / DATA SHEET Date: Lab : MT Lab Name: Class: III Sem USN: Expt.No:

Title of the Experiment: IMPACT TEST--- IZOD OBSERVATIONS: Least count of Vernier Calliper:0.02mm Least count of the Dial on the Impact testing machine = 0.1 kg-m EXPERIMENTAL READINGS: Dial Reading (Kg-m) Material Mild Steel Dimensions of the specimen Length = 27.0mm. Diameter =12mm Dia. of notch=9mm Depth of notch =1.5mm Width of notch = 3.0mm Length = 25.0mm Diameter = 11.0mm Dia .of notch = 7.84mm Depth of notch=1.58mm Width of notch = 3.0mm Notch angle 45 Initial (E1) 0 Final (E2) 1.5 Energy consumed (Kg-m) 1.5

Cast Iron

45

0

0.1

0.1

Material Testing lab Manual

Department of Industrial Engineering and Management, R.V. College of Engineering, Bangalore 59.

Signature of the staff in charge

Material Testing lab Manual

Department of Industrial Engineering and Management, R.V. College of Engineering, Bangalore 59.

PROCEDURE: 1. Raise the pendulum and fix it to the pendulum notch. Place a thick wooden plank on the stand below the pendulum pipe. 2. Keep the reading pointer at 17 kg-m on the inner scale. Release the Izod lever and allow the pendulum to swing freely. Arrest the movement of the pendulum by using the pendulum brake. 3. Record the indicator reading, which will give the energy lost due to friction and air drag. See if the pointer comes to o (Zero) reading. If not, there will be on error (in calibration of the instrument). Note that as initial reading. Again raise the pendulum and fix it onto the notch. 4. Measure the lateral dimension of the specimen at the full section and at the notch and check whether the dimensions conform to the given standard, 5. Now fix the Izod specimen inside the damping device, hold the specimen in hand vertically such that the half of the V-notch is just above the horizontal surface of the clamping device (cantilever beam position) and the notch is facing the pendulum. 6. Now insert the setting gauge such that the pointer edge of the setting gauge correctly fits inside the V-groove. Simultaneously tighten the clamping screw using allen key and check that there is no movement of the specimen. 7. After ascertaining that, there will be nobody in the range of swinging the pendulum. 8. Operate the Izod lever. Now the pendulum will swing freely and the specimen will be smashed. Care must be taken to see that proper range is selected on the indicator (The circular opening in the dial should be fully-3/4th red and partly black) 9. Stop the swinging pendulum by applying the pendulum brake. 10. Note the reading on the dial corresponding to the pointer. 11. Calculate the difference between final and initial readings. This value gives the impact energy consumed or lost in breaking the specimen.

Material Testing lab Manual

Department of Industrial Engineering and Management, R.V. College of Engineering, Bangalore 59.

TABULATION AND CALCULATION:Material Dial Reading Initial E1 (Kg-m) Mild Steel Cast Iron 0 0 Final E2 (Kg-m) 1.5 0.1 Energy consumed (E2- E1) (Kgm) 1.5 0.1 Energy Consumed (E2- E1) , J

14.715 0.981

SPECIMEN CALCULATION (For Mild Steel):-

Actual energy absorbed by the specimen during fracture = Energy recorded on the dial indicator with specimen in position - Energy recorded on the dial indicator without specimen in position. = 1.5- 0 = 1.5 Kg-m = 1.5x9.81 = 14.715 J RESULTS:The actual energy absorbed by the specimens is as follows: 1. Mild steel = 14.715 J 2.Castiron = 0.981J

Material Testing lab Manual

Department of Industrial Engineering and Management, R.V. College of Engineering, Bangalore 59.

Material Testing lab Manual

Department of Industrial Engineering and Management, R.V. College of Engineering, Bangalore 59.

R.V. COLLEGE OF ENGINEERING, BANGALORE-560059 DEPARTMENT OF INDUSTRIAL ENGG. AND MANAGEMENT MATERIAL TESTING LABORATORY OBSERVATION / DATA SHEET Date: Lab : MT Lab Name: Class: III Sem USN: Expt.No:

Title of the Experiment: IMPACT TEST---CHARPY OBSERVATIONS: Least count of Vernier Calliper:0.02mm Least count of the Dial on the Impact testing machine =0.1Kgm EXPERIMENTAL READINGS: Dial Reading (Kg-m) Initial (E1) 0 Final (E2) 1.05 Energy consumed 1.05

Material

Dimensions of the specimen

Notch angle

Brass

Length = 60 mm Breadth = 10 mm Width of the notch=10mm Depth of notch=02 mm Length = 56.20 mm Breadth = 9.76 mm Width of the notch=10mm Depth of notch=02 mm

900

Mild Steel

900

0

3.8

3.8

Signature of the staff in charge

Material Testing lab Manual

Department of Industrial Engineering and Management, R.V. College of Engineering, Bangalore 59.

RESULT : DIMENSIONS OF SPECIMEN BEFORE TESTING SL. NO. 1 2 3 PARAMETERS Length of the specimen (mm) Breadth of the specimen (mm) Thickness of the specimen (mm) MATERIALS BRASS MILD STEEL 56.20 55.20 9.76 9.72 9.72 9.64

SPECIMEN CALCULATION BRASS Actual energy absorbed by specimen during fracture = Energy recorded on the dial indicator with specimen in position - Energy recorded on the dial indicator without specimen in position = 1.05-0 = 1.05 kg-m = 1.05x9.81 = 10.30 N-m = 8.829 J RESULTS: The actual energy absorbed by the different specimens are as follows:Brass: - 10.3 J Mild steal: -37.27 J

Material Testing lab Manual

Department of Industrial Engineering and Management, R.V. College of Engineering, Bangalore 59.

EXPERIMENT No. D01

NON -DESTRUCTIVE TESTSINTRODUCTION: A Non - destructive test is an examination of a component in any manner which will not impair its future use. Although non-destructive test do not provide a direct measurement of mechanical properties, but they are very useful in revealing defects in components which could impair their performance when put in service. Non destructive tests make components more reliable, safe and economical.

ULTRASONIC TEST AIM: To study the ultrasonic flaw detector and to determine the location of the interior crack or cavity in the given specimen. APPARATUS: Ultrasonic flaw detector. THEORY: Ultrasonic flaw detector is a device, which is used to detect internal discontinuities in the material by nondestructive means. It makes use of phenomenon of back reflection (echo) of waves by surfaces. When ultrasonic waves are made to pass through the test material, portion of the sound is immediately reflected from the surface at which they enter as a very large echo. Part of the sound will continue on into the test material, until it is partially reflected from the back surface as a second echo. If there is a discontinuity in the material, a portion of the sound will be reflected from the discontinuity and will return to the receiver as a separate echo between the echoes received from the front and back surface. The signals received are shown on a cathode ray tube, which also has a time base connected to it, so that the position of the signal on the screen gives an indication of the distance between the crystal generator and the surface from which the echo originates. Sound waves oscillating with a frequency greater than 20,000 cps are inaudible and are known as ultrasound. High frequency sound is produced by a piezoelectric crystal, which is electrically pulsed and then vibrates at its own natural frequency. In order to transmit the sound waves from the crystal to the metal, it is necessary to provide a liquid couplant. This is accomplished by using a film of oil between the crystal and the test piece. After the crystal has given off its short burst of sound waves, it stops vibrating and listens for the returning echoes, i.e., one crystal probe is used to send and receive the sound. This cycle of transmitting and then receiving is repeated at an adjustable rate from 100 to 1000 times per second. Returning echoes on the CRT causes short vertical spikes called pips. These are spaced along the baseline according to their time of receipt. Since the sound travels through the material at a constant speed, the spacing of the pips can be considered as indicating thickness. Selecting and expanding full screen size of the CRT can eliminate unwanted echoes caused by reverberations with the test piece.

Material Testing lab Manual

Department of Industrial Engineering and Management, R.V. College of Engineering, Bangalore 59.

PROCEDURE: 1. Clean the surface of the test piece. 2. Place the probe against the surface of test piece using thin oil film. 3. Switch on the power supply of the ultrasonic wave generator. 4. Adjust the number of cycles of transmitting and receiving the signals to the desired value. 5. Select the segment of time, which contain the echo pips. 6. Observe the echo from the cavity if any on the CRT and measure the relative distances of pips on the time axis. Let A = Time elapsed between the pips of front surface echo and bottom surface echo (sec) B = Time elapsed between the pips of front surface echo and cavity surface echo (sec) H = Thickness of test specimen (mm) Location of the crack from the front surface x = (B/A)x h ADVANTAGES: 1. It is a fast, reliable method of non destructive inspection 2. It is a very sensitive method. 3. The minimum flow size which can be detected is equal to about 0.1% of the distance from the probe to the defect. 4. Big castings can be systematically scanned for initial detection of major defects. 5. Ultrasonic inspection involves low cost and high speed of operation. 6. The sensitivity of ultrasonic flow detection is extremely high, being at a maximum when using waves of highest frequency. LIMITATIONS: 1. Ultrasonic inspection is sensitive to surface roughness since cost surfaces are usually rough, some preliminary machining an castings will be required. 2. In complex castings the interpretation of the oscillographic trace may not be easy. Waves reflected from corners or other surfaces may give a false indication of defects. APPLICATIONS: 1. Inspection of large castings and forgings, for internal soundness, before carrying out expensive machining operations 2. Inspection of moving strip or plate (for laminations) as regards its thickness. 3. Routine inspection of locomotive axles and wheel pins for fatigue cracks. 4. Inspection of rails for bolt-hole breaks without dismantling railed assemblies.

Material Testing lab Manual

Department of Industrial Engineering and Management, R.V. College of Engineering, Bangalore 59.

MAGNETIC PARTICLE TESTAIM: To detect the surface or subsurface crack of the given ferromagnetic material. APPARATUS: Magnetic field generator and ferromagnetic powder.Magnetic particles U-Horse Magnet

THEORY: The magnetic particle method of inspection is aof Crack Location procedure used to determine the presence of defects at or near the surface of the ferromagnetic objects. This method consists of placing fine ferromagnetic particles on the surface. The particles can be applied either dry or in a liquid carrier such as water or kerosene. When the part is magnetized with a magnetic field, a discontinuity (defects) on the surface causes the particles to gather visibly around it. Thus, the defects become a magnet due to the principle of flux leakage where magnetic field lines are interrupted by the defect and collect the ferromagnetic particles. The collected particles generally take the shape and size of the defects. Sub surface defects can also be detected by this method, provided they are not deep. The ferromagnetic particles may be colored with pigments for better visibility on the metal surfaces. The magnetic fields can be generated either with direct current or alternating current, using yokes, bars and coils. The equipment may be portable or stationery. Procedure: 1. Clean the surface of the test specimen to remove scales, oil and grease. 2. Apply a thin layer of ferromagnetic particles over the surface to be tested. 3. Magnetize the test piece. 4. Observe the shape and size of the magnetic particles collected, which is the shape and size of the defect.

VISUAL INSPECTIONDefects like surface cracks, tears, blowholes, metal penetration, rattails and buckles, swells, shifts, surface roughness and shrinkage are easily located by visual inspection. It is carried out with the marked eye or using a magnifying glass. This method is the simplest, fastest and most commonly employed, but requires greater skill on the part of the inspector to locate and identify different manufacturing defects. The inspector identifies the casting defects and assigns their cause to some foundry operation or raw materials so that corrective measures can be employed. Visual inspection ensures that none of the features of a casting has been omitted or malformed by moulding errors short running or mistakes in fitting.Material Testing lab Manual

Department of Industrial Engineering and Management, R.V. College of Engineering, Bangalore 59.

LIQUID PENETRANT TESTAIM: To detect the surface defects by penetrant test. APPARATUS: Penetrant, developer and ultraviolet light source. THEORY: In the liquid penetrant test, liquids are applied to the surface of the part and allowed to penetrate into surface openings, cracks, seams and porosity. Two commonly known types of liquid penetrants are: (a) (b) surface. Fluorescent Penetrants which fluoresce under ultraviolet light, and Visible penetrant using dyes, usually red if which appear as bright outlines on the

The test piece is coated or socked in a liquid penetrant and the surplus coating is wiped off. After a short time, a developing agent is added to allow the penetrant to seep back to the surface (due to capillary action) and spread to the edges of openings. The surface is then inspected for defects, either visually in the case of dye-penetrants or under ultraviolet light for fluorescent penetrant. The developer includes dry powders, aqueous liquid and non-aqueous liquid. This method is capable of detecting variety of surface defects and is used extensively. PROCEDURE: 1. Clean the test piece surface to remove scales, oil and grease. 2. Immerse the test piece in the selected penetrant and hold it for some time. 3. Remove the excess penetrant on the test piece surface. 4. Apply the developer on the surface of the test piece. 5. Examine the surface of the test piece under appropriate viewing conditions. 6. Clean the surface to prevent corrosion, etc. OTHER NON-DESTRUCTIVE TESTS 1. Hammer Test 2. Radiography Test X- Ray radiography Gamma-ray radiography 3. Testing for metal composition -Wet analysis - Spectroscopy - Spot test techniques. EXPERIMENT No. MT04

ROCKWELL HARDNESS TESTMaterial Testing lab Manual

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AIM:- To determine the Rockwell hardness number of the given specimen. APPARATUS / INSTRUMENTS / EQUIPMENT USED: Rockwell Hardness tester Indentors ROCKWELL HARDNESS TESTER

Equipment Description: Rockwell HTM impacts a standard load on a steel ball or diamond indenter. Rockwell hardness test determines the hardness of ceramic substrates. The most common method of calculating hardness of plastics such as nylon, polycarbonate, polystyrene, and acetal is done by Rockwell hardness test. This test is also used for measuring the resistance of the plastic to indentation. The dial gauge is used to calculate the difference in depth produced by two different forces. The load applied, indenter diameter and the indentation depth can be measured using Rockwell hardness value.

Material Testing lab Manual

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R.V. COLLEGE OF ENGINEERING, BANGALORE-560059 DEPARTMENT OF INDUSTRIAL ENGG. AND MANAGEMENT MATERIAL TESTING LABORATORY OBSERVATION / DATA SHEET Date: Lab : MT Lab Name: Class: III Sem USN: Expt.No:

Title of the Experiment: ROCKWELL HARDNESS TEST

OBSERVATIONS AND TABULATION SL.NO 1 2 3 4 5 Material Mild steel Cast Iron Brass Copper Aluminium Scale C C B B B Load(Kg) 150 150 100 100 100 Indenter Cone(120) Cone(120) Ball (1/16th Ball (1/16th Ball (1/16th Rockwell Hardness Number Trail 1 Trail 2 Trail 3 107 107 108 93 94 93 48 51 46 91 95 101 52 54 52

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Material Testing lab Manual

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SELECTION OF LOAD AND INDENTOR Scale Symbol A B C Major Load (Kg) 60 100 150 Indentor Cone (1/16) Ball Cone Application Cemented carbide, thin steel, hardened steel. Copper alloys, Soft Steels, Aluminum Alloys, Malleable Iron Steel, Hard cast Iron, Paralyte malleable Iron, Deep case hardened steel.

PROCEDURE 1. Place the specimen on the anvil. 2. Select the load and indentor combination based on specimen material. 3. Raise the anvil until the specimen comes in contact with the indentor. Continue to raise the anvil slowly till the pilot lamp goes off. This indicates that the minor load of 10 kg is acting on the indentor. 4. Actuate the lever to apply the major load. 5. Give at least 10 seconds after the lever comes to rest position. 6. Read the position of the pointer on the corresponding scale of the dial, which gives the Rockwell hardness number. 7. Make three tests on each specimen. 8. Calculate average Rockwell hardness number. 9. Plot the bar chart separately for B-Scale and C-Scale

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TABULATION AND CALCULATIONS:SL. NO 1 2 3 4 5 Material Mild steel Cast Iron Brass Copper Aluminium Scale C C B B B Load(Kg) 150 150 100 100 100 Indenter Cone(120) Cone(120) Ball dia (1/16th of an inch) Ball dia (1/16th of an inch) Ball dia(1/16th of an inch) Rockwell Hardness Number Trial Trial 2 Trial 3 Avg.RHN 1 107 107 108 107.33 93 94 93 93.33 48 91 52 51 95 101 54 52 52.66 95.66 46 48.33

SPECIMEN CALCULATION:Material : BRASS Scale : B-Scale Indentor = 1/16 Ball Indentor Major Load Applied = 100 Kgs Rockwell Number for trail 1, RHN1 = 48 Rockwell Number for trail 2, RHN2 = 51 Rockwell Number for trail 3, RHN3 = 46 Average Rockwell Number = (RHN1+RHN2+ RHN3) / 3 = (48+51+46) / 3 = 48.33 Kg/cm2 RESULTS:MATERIAL Cast Iron Mild Steel Brass ROCKWELL HARDNESS NUMBER 93.33 107.33 48.33

Material Testing lab Manual

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Copper Aluminium C Scale110 Rockwell Hardness No. 105 100 95 90 85 Cast Iron Materials 93.33 107.33

95.66 52.66

Mild Steel

B Scale

120 Rockwell Hardness No. 100 80 60 40 20 0 Brass Copper Materials Aluminium 48.33 52.66 95.66

Material Testing lab Manual

Department of Industrial Engineering and Management, R.V. College of Engineering, Bangalore 59.

EXPERIMENT No. MT06

DOUBLE SHEAR TESTAIM:- To conduct a Double shear test on different materials and obtain their shear strengths. APPARATUS / EQUIPMENT / INSTRUMENTS USED: Universal testing machine, Vernier calipers, Double shear shackles. UNIVERSAL TESTING MACHINE

DOUBLE SHEAR SHACKLES AND SPECIMEN:

Material Testing lab Manual

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R.V. COLLEGE OF ENGINEERING, BANGALORE-560059 DEPARTMENT OF INDUSTRIAL ENGG. AND MANAGEMENT MATERIAL TESTING LABORATORY OBSERVATION / DATA SHEET Date: Lab : MT Lab Name: Class: III Sem USN: Expt.No:

Title of the Experiment: DOUBLE SHEAR TEST OBSERVATIONS: Least count of vernier caliper =0.02mm TABULATION Sl. No. 1 2 MATERIAL Brass Mild Steel DIAMETER (mm) 7.7 7.7 Failure Load (Kg) 3200 4300

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Material Testing lab Manual

Department of Industrial Engineering and Management, R.V. College of Engineering, Bangalore 59.

PRINCIPLE: Shear stress is caused by forces which act parallel to in area if cross-section and tend to produce sliding of one portion past another portion as shown in figure below:

P

If the force is resisted by failure through one plane and single area, then the material is said to be in single shear. In single shear, = Where, failure load P P 4P = = = N / m2 2 2 area of cross section A D 4 D D - initial diameter of the specimen. P - failure load.P P

If 2 areas resist the fracture, then the area is said to be in double shear.

=

Failure Load P 2P = = N / m2 2 2 Area of cross section 2 A D

For conduction shear test, a suitable steel shackle may be fabricated based upon fork and eye plate principle the specimen is inserted as a connecting pin in the bush housing between the shackles; the fork plates of the shackle held rigidly together by bolts for avoiding any bending tendency of the specimen under high loads, and is tested in double shear. 1. The diameter of the specimen is measured using vernier calipers and the area of cross section of the specimen is calculated. 2. The specimen is than inserted inside the shear shackles & is placed inside the shear center plate. 3. The entire assembly is then placed on the lower cross slide of the universal testing machine.

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4. The intermediate cross slide is then moved down till it makes contact with the top of the centre plate, through which the load is applied on the specimen. 5. The machine is started and the load is applied gradually till the specimen fails. At this point note down the load and the corresponding dial gauge reading. OBSERVATION: Sl. MATERIAL No. 1 Brass 2 Mild Steel

DIAMETER (mm) 7.7 7.7

Failure Load (Kg) 3200 4300

CALCULATION OF DOUBLE SHEAR STRENGTH MILD STEEL Area of cross section, ( 7.7 ) 2 = 46.566mm 2 d 2 A= = 4 4 = 46.566 10 -6 m 2 Double strength,

=

Failure Load 4300 9.81 = = 452.937 10 6 N / m 2 6 2 Area of cross section ( 2 46.566 10 )

BRASS Area of cross section, Double strength, A=

( 7.7 ) = 46.566mm 2 d 2 = 4 4 = 46.566 10 -6 m 22

=

Failure Load 3200 9.81 = = 337.069 10 6 N / m 2 6 2 Area of cross section ( 2 46.566 10 )

RESULT: SL.N0 1 2 DOUBLE SHEAR STRENGTH MILD STEEL 452.937 X106 N/m2 BRASS 337.0699 X106 N/m2 EXPERIMENT No. D02 MATERIAL

Material Testing lab Manual

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FATIGUE TESTAIM: To determine the fatigue limit and the fatigue strength. APPARATUS: Fatigue testing machine and micrometer caliper. THEORY: Failure due to repeatedly applied load is known as fatigue. The physical effect of a repeated load on a material is different from the static load, failure always being brittle fracture regardless of whether the material is brittle or ductile. Mostly fatigue failure occurs at stress well below the static strength of the material. If the applied load changes from any magnitude in one direction to the same magnitude in the opposite direction, the loading is termed completely reversed, where as if the load changes from one magnitude to another (the direction does not necessarily change), the load is said to be fluctuating load. Fatigue testing machine: In the simplest type of machine for fatigue testing, the load applied is of bending type. The test specimen may be of simply supported beam or a cantilever. R.R.Moore rotating beam type machine for a simply supported beam.A specimen of circular cross-section is held at its ends in special holders and loaded through two bearings equidistant from the center of the span. Equal loads on these bearings are applied by means of weights that produce a uniform bending moment in the specimen between the loaded bearings. A motor rotates the specimen. Since the upper fibers of the rotating beam are always in compression while the lower fibers are in tension, it is apparent that a complete cycle of reversed stress in all fibers of the beam is produced during each revolution. A revolution counter is used to find the number of cycles the specimen is repeatedly subjected to the load. For simply supported beam, maximum bending moment is at the center. The testing techniques are subjected to a series of identical specimens to loads of different magnitudes and note the number of cycles N of stress (or load) necessary to fracture the specimen. The data are plotted on a semi logarithmic paper, the stress S being plotted to a linear scale and the number of cycles N to a logarithmic scale.This is known as stress-cycle (S-N) diagram and the fatigue limit can be, determined from the diagram. Fatigue limit or endurance limit is the stress below, which a material can be, stressed cyclically an indefinitely large number of times without failure. The fatigue strength is the stress at which a metal fails by fatigue after a certain number of cycles. Specimens: All specimens should be taken from the same rod, each specimen should receive same kind of machining and heat treatment. The specimens for tests have no sharp stress raisers. The surface of the specimen is polished. Fracture appearance: Under repeated loading, a small crack forms in a region of high-localized stress, and a very high stress concentration accompanies the crack. As the load fluctuates, the crack opens and closes and progresses across the section. Frequently this crack propagation continues until there is in sufficient cross section left to carry the load and the member ruptures, the failure being fatigue failure. Therefore fractured surface shows two surfaces of distinctly different appearance. 1. A smooth surface where the crack has spread slowly and the walls of the crack are polished

Material Testing lab Manual

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by repeated opening and closing. This surface usually shows characteristic of beach or clamshell marking. 2. A crystalline or fibrous surface where sudden failure occurred. PROCEDURE: 1. 2. 3. 4. Measure the diameter d and the length L of the specimen. Fasten the specimen in the chucks of the testing machine. Set the maximum load. Set the counter to zero, and start the machine. Note the number of cycles N the specimen experiences before fracture.

5. Repeat the above test on the other specimens with gradually reduced loads. Draw the S-N diagram and obtain the endurance limit.

Material Testing lab Manual

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EXPERIMENT No. MT10 BENDING TEST AIM:- To conduct the bending test on the given material and there by determine the following: i. ii. iii. iv. Stiffness Maximum bending moment Maximum bending stress at failure Modulus of elasticity

APPARATUS/EQUIPMENT/INSTRUMENTS USED

Universal Testing Machine Cathetometer Bending test attachment Former (acting as a knife edge to apply a concentrated load at the center of the specimen) Cathetometer

The Cathetometer can measure with great precision the difference in level between two points whether or not they lie on the same vertical line. This instrument is made of a robust graduated vertical copper rod, more than a meter long. The rod turns on its axis and is mounted on a tripod with leveling screws. Attached to the rod are two horizontal collimeter telescopes attached to tracks which have a ruler and a pointer and which can slide along the rod. The instrument's case has the form of a right angle prism and rests on a strong metallic tripod. Less sophisticated cathetometers have one telescope with which the two points are collimated successively.

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If two points, A and B, are collimated through the telescopes and the positions assumed by the two pointers are read on the scale, the difference between gives the distance between the horizontal planes of the two points. The collimation is effected by creating a coincidence between the image of the point (observable through the telescopes) and the center of the instrument's optical grid. The degree of precision obtained in measurement depends on the approximation obtained with the ruler and on the care with which the graduated rod is put vertical and the telescopes horizontal.

Material Testing lab Manual

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R.V. COLLEGE OF ENGINEERING, BANGALORE-560059 DEPARTMENT OF INDUSTRIAL ENGG. AND MANAGEMENT MATERIAL TESTING LABORATORY OBSERVATION / DATA SHEET Date: Lab : MT Lab Name: Class: III Sem USN: Expt.No:

Title of the Experiment: BENDING TEST OBSERVATIONS Least count of vernier caliper = 0.02mm Least of cathetometer = 0.01mm MATERIAL SPECIFICATIONS Length (l) mm Breadth (b) mm Thickness (d) mm 400 46 71

LOAD AND DEFLECTION READINGS Cathetometer initial reading = 17.272mm Sl. No Load (Kg) MATERIAL: MATTI WOOD Final Reading Final-Initial Reading 1 0 17.272 0 2 300 17.403 0.131 3 600 17.413 0.141 4 900 17.413 0.141 5 1200 17.541 0.269 6 1500 17.788 0.516 7 1800 18.007 0.735 8 2100 18.126 0.854 9 2400 Breaking point

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Material Testing lab Manual

Department of Industrial Engineering and Management, R.V. College of Engineering, Bangalore 59.

A bending test can be performed on an actual being cross -section by using a 3-point loading system. The bending fixture is supported on the platform of the hydraulic cylinder of the UTM , The loading edge is held in the middle or intermediate crosshead. At a particular load , the deflection at the centre of the beam is determined using a dial gauge. The deflection at the centre of the beam is given by = W L 3 / (48 E I ) E = W L 3 / (48 I ) Stiffness , W/ = 48 EI/ L3 This is derived from the bending equation , M/I = / y = E/R The beam with simply supported at two ends and loaded at the centre is as shown in figureW

L/2 W/2 For the above beam

L/2 W/2

Maximum bending moment = WL/4 Since cross section of beam is rectangle with dimensions b&d, I = bd3 / 12 Therefore, s = 3WL / (2d3) N/m2 Where L = Length of the specimen in meters, b = breadth of the specimen in meters , d = depth or thickness of the specimen in meters , W= Applied load in N

Material Testing lab Manual

Department of Industrial Engineering and Management, R.V. College of Engineering, Bangalore 59.

PROCEDURE 1. The bending test attachment is fitted in the universal testing machine and the specimen is fixed in it using the special shackles provided for the purpose. 2. The breadth and thickness of the specimen are measured using vernier caliper and its length determined after fixing 3. The loading former is fixed in the intermediate cross head firmly and is adjusted till it just touches the specimen. 4. Record the initial cathetometer reading . 5. Load is applied, and after every 300 Kg, the cathetometer is focused on the wood specimen and the corresponding reading recorded. 6. Loading is continued till the specimen fails 7. Calculations are made. 8. A graph of load against deflection is plotted. Principal features of supporting and loading devices for BEAM TESTS indicating provision for longitudinal and lateral rotational adjustment at support

DEFLECTION MEASURING DEVICES

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BENDING OF A BEAM

MATERIAL: TEAK WOOD BENDING MOMENT CALCULATIONS SL. NO. 1 2 3 4 5 6 7 8 9 10 11 LOAD W (X9.81 N) 0 300 600 900 1200 1500 1800 2100 2400 2700 3000 DEFLECTION READING (mm) 162.60 162.60 162.60 162.60 162.60 162.60 162.60 162.60 162.60 162.60 162.60 162.60 163.53 164.03 164.42 165.16 165.34 165.50 166.00 166.64 166.80 167.32 0 0.93 1.43 1.92 2.56 2.74 2.90 3.40 4.04 4.20 4.72 Bending moment (N-m) 0 286.94 573.89 860.83 1147.77 1434.71 1721.66 2008.60 2295.54 2582.48 2869.43

MATERIAL : MATTI WOOD BENDING MOMENT CALCULATIONS LOAD W (X9.81 N) 1 2 3 0 300 600 DEFLECTION (mm) INITIAL 17.272 17.272 17.272 FINAL 17.272 17.403 17.413 = Final Initial 0 0.131 0.141 Bending moment (N-m) 0 286.94 573.89

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4 5 6 7 8 9

900 1200 1500 1800 2100 2400

17.272 17.272 17.272 17.272 17.272 17.272

17.413 17.541 17.788 18.007 18.126 Breaking point

0.141 0.269 0.516 0.735 0.854

860.83 1147.77 1434.71 1721.66 2008.60

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DEFELECTION vs LOAD GRAPH FOR TEAK WOOD3500 3000 LOAD (X9.81 N ) 2500 2000 1500 1000 500 0 0 0.93 1.43 1.92 2.56 2.74 2.9 3.4 4.04 4.2 4.72 DEFLECTION (X0.001 m)

DEFLECTION vs LOAD FOR MATTI WOOD1600 1400 1200 1000 800 600 400 200 0 0 1.15 1.65 2.25 1.05 3.35

LOAD (X9.81 N)

DEFLECTION (X0.001 m)

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SPECIMEN CALCULATION MATERIAL : TEAK WOOD (Sl. No. 2) 1. Deflection, = Final reading - Initial reading = (17.541-17.272) =26.9 x 10-3 m 2. Load, W = 1200 Kg = 1200 x 9.81= 11772 N Length of the specimen, l = 400.0 mm = 0.4 m Breadth of the specimen, b =47.0 mm = 0.47m Thickness of the specimen, d = 71.0 mm = 0.071m 3. Bending moment, M = W l / 4 = 11772x 0.4 /4 = 1177.2 N-m 4 Maximum bending moment = Wmax x l /4 = 3000 x9.81 x 0.39/4 = 2869.43N-m 5 Momentum of inertia, I = bd3/12= 0.47 x (0.71 )3/12 = 1.4018 x 10-6 m4 6 Stiffness = W / = 2400 x 9.81/ 26.9 x 10 3 N/m = 875.24 x 103 N/m 7 Maximum bending stress = 3 Wmax L/ ( 2 bd2 ) = 3 x 3000 x 9.81 x 0.4 / (2 x 0.071 x (0.047)2) = 91.82 x 106 N/m2 8 From graph W vs , W = 2500x9.81 N = 3.9 x 10-3 m Now, Youngs Modulus, E = WL3 / (48 I ) = 4.28 x 1015 N/m2 RESULT : SL. No 1 2 3 4 PROPERTIES MATERIALS TEAK WOOD Modulus of Elasticity (Youngs Modulus) ( N/m2) Maximum Bending (N-m) Stiffness (N/M) 9.95 x 109 2869.43 6.29 x 106 91.82 x 106 MATTI WOOD 6.19 x 109 1397.93 4.04 x 106 44.17x106 = 0.269 mm

CONCLUSION: From above results, it can be concluded that Teak Wood is having more strength than Matti WoodMaterial Testing lab Manual

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EXPERIMENT No. MT08

BRINELL HARDNESS TESTAIM:- To find out the Brinell Hardness Number for the given specimen/s of ferrous metals (mild steel, cost iron) and non-ferrous metals (copper, Brass) APPARATUS / EQUIPMENT/INSTRUMENTS USED: Brinell hardness testing machine , Ball Indentor Traveling microscope . Brinell Hardness Testing Machine

Equipment Description:Brinell HTM measures the resistance of a material to the penetration of a hardened steel ball subjected to a standard load. This Hardness Tester uses a machine to measure hardness by determining the depth of penetration of a spherical shaped device under controlled conditions. A carbide sphere of a specified diameter under a specified load is applied to the surface of the material and the diameter of the indentation is measured. The diameter of the indentation made is measured with the aid of Microscope. The Brinell hardness value is obtained by dividing the load to the actual surface area. This number is used to make relative comparisons of the different materials. The formula used to calculate the Brinell hardness number is as follows:

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Brinell Hardness Number (BHN) = F/[/2 (D-D- Di)] Where F - Applied Load D - Diameter of the spherical indenter Di -Diameter of the resulting indenter impression These machines are robustly built to provide laboratory accuracy in the harshest industrial environments and are used all over the world. The only disadvantage is more time is consumed for measuring hardness.

Material Testing lab Manual

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R.V. COLLEGE OF ENGINEERING, BANGALORE-560059 DEPARTMENT OF INDUSTRIAL ENGG. AND MANAGEMENT MATERIAL TESTING LABORATORY OBSERVATION / DATA SHEET Date: Lab : MT Lab Name: Class: III Sem USN: Expt.No:

Title of the Experiment: BRINELL HARDNESS TEST OBSERVATIONS: Diameter of ball indenter =2.5mm Least count of micrometer =0.001mm TABULATION: Sl. No. 1 2 3 4 MATERIAL Steel Cast Iron Brass Copper LOAD (KG) 187.5 187.5 62.5 62.5 Duration of loading (sec) 15 15 15 15 Diameter of indentation(mm) 1.117 1.255 1.247 1.043 1.031 1.045 0.82 0.812 0.831 0.965 0.955 0.975

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DERIVATION FOR BRINELL HARDNESS NUMBER The principle of the Brinell Hardness Number is as shown in Figure . From the geometry of the figure,

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h = depth of indentation in mm d = diameter of indentation in mm D = diameter of indentor ball in mmO

From triangle OAE, OA =Sqrt ( OE2 EA2) = Sqrt[( D/2)2 (d/2)2] h = OB- OA = D/2 - Sqrt[( D/2)2 (d/2)2] Area of spherical indentation, A = P x DXh=P x Dx{D/2 - Sqrt[( D/2)2 (d/2)2]} = P x (D/2) x{ D - Sqrt[( D)2 (d)2]} BHN = Load / Area of spherical indentation = P P x (D/2) x[( D Sqrt [( D)2 (d)2] Cross Sections of Indentation in Brinell Test

D/2 C A B d

D/2 E

hh

PROCEDURE: 1. Place the polished specimen on the platform. 2. Raise the platform till the surface of the specimen gets focused on the microscope screen.Material Testing lab Manual

Department of Industrial Engineering and Management, R.V. College of Engineering, Bangalore 59.

3. Select the load by pressing the load selector. Load P : 30XD2 for ferrous materials :10 D2 For non ferrous materials : 5 D2 for soft metals and alloys Where P is the load in kg. and D is the diameter of the indentor in mm. 4 Press the actuator in position,then the load acts on the indentor. 5. Wait till the handle on the left side of the frame comes to rest position. Now allow the load to act for 15 seconds for ferrous materials and 30 seconds for non ferrous materials. 6. Press the handle down without jerk to release the load and to bring the objective lens back into position 7. Measure the diameter of the indentation using the micrometer and microscope 8. For each materials make at least three indentations and measure the diameters. 9. Calculate the BHN for each diameter obtained and take the average of the three. 10. Tabulate the results. 11. Draw the Bar chart TABULATION AND CALCULATIONS Sl No 1 2 3 4 Material Load (Kg) 62.5 62.5 187.5 187.5 Duration Of Loading (Sec) 30 30 15 15 Diameter of Indentation (mm) 0.965 0.82 1.117 1.043 0.955 0.812 1.255 1.031 0.975 0.831 1.247 1.045 Average BHN (X108N/M2) 8.05 11.478 15.394 21.112

COPPER BRASS MILD STEEL CAST IRON

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SPECIMEN CALCULATION MATERIAL : COPPER Applied Load, P = 62.5 Kg. Diameter of Ball, D = 2.5 mm Avg.Diameter of Indentation, d= 0.965 mm BHN = P / [ x (D/2) x (D- Sqrt D2 d2)] = 62.5 / [ x(2.5/2)x(2.5 Sqrt (2.5)2 (0.965)2)] = 82.143Kg / mm2 = 82.143x9.81 N /mm2 = 8.05 x 108 N/m2 RESULT: 1. Bar chart was drawn for the given materials 2. The BHNs of the given materials are as shown in below: SL. NO 1 2 3 4Brinell Hardness Number 25 20 15 10 5 0 COPPER BRASS MILD STEEL CAST IRON 8.05 11.478 15.394

MATERIAL

COPPER BRASS MILD STEEL CAST IRON

BRINELL HARDNESS NUMBER (X108N/ m2) 8.05 11.478 15.394 21.112

21.112

Materials

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Department of Industrial Engineering and Management, R.V. College of Engineering, Bangalore 59.

EXPERIMENT No. MT09

VICKERS HARDNESS TESTAIM: - To determine the Vickers Hardness number of the given material APPARATUS/EQUIPMENT/INSTRUMENTS USED: Vickers Hardness Tester, Diamond pyramid indentor. Vickers Hardness Testing Machine

Vickers HTM is used to measure hardness of metals with hard surfaces. It is measured from the size of an impression produced under standard load by a diamond indenter used, which is pyramidshaped. The diagonal length is measured with a Microscope. The formula used to calculate the Vickers Hardness Number is as follows: Vicker Number (HV) = 1.854(F/ D) Where, F - Applied Load, D - Indentation Area

Advantages of Vickers Hardness Tester The diagonal of the square can be measured easily and accurately Easier method for testing harder materials. Disadvantages of Vickers Hardness Tester More Complicated & Expensive

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Department of Industrial Engineering and Management, R.V. College of Engineering, Bangalore 59.

R.V. COLLEGE OF ENGINEERING, BANGALORE-560059 DEPARTMENT OF INDUSTRIAL ENGG. AND MANAGEMENT MATERIAL TESTING LABORATORY OBSERVATION / DATA SHEET Date: Lab : MT Lab Name: Class: III Sem USN: Expt.No:

Title of the Experiment: VICKERS HARDNESS TEST OBSERVATIONS: Indentor = Square pyramid indentor Least count of traveling micrometer =0.001mm TABULATIONS Sl. No. MATERIAL Standard Load P (Kg) 20 30 30 20 20 0.500 0.501 0.618 0.569 0.500 Diagonal width (mm) d1 0.500 0.530 0.610 0.553 0.500 0.486 0.544 0.625 0.558 0.486 0.500 0.559 0.618 0.547 0.500 d2 0.467 0.516 0.620 0.547 0.467 0.500 0.539 0.613 0.548 0.500

1 2 3 4 1

BRASS CAST IRON MILD STEEL COPPER BRASS

Signature of the staff in charge

Material Testing lab Manual

Department of Industrial Engineering and Management, R.V. College of Engineering, Bangalore 59.

THEORY :Vickers hardness number indicate the extent of resistance offered by the material to permanent indentation under static loading . The test consists in forcing a square based diamond pyramid (with an angle of 136 0 between opposite faces) into the ground or polished surface to be tested. The pyramidal indentor makes impressions that remain geometrically similar irrespective of its size. The hardness number is derived from the relationship between the applied load and the surface area of the indentation. Definition: Vickers hardness number is defined as the ratio between load and surface area of the impression and is calculated by formula, Vickers hardness number (VHN) = 2 P sin (q/2)/ d2 = (1.854xP/d2) Kg/mm2 =(18.188 x 106 x P/d2) /m2 Where P = applied load in kg d = Length of diagonal of indentation in m = apex angle of the pyramidal indentor PRINCIPLE :-

Diamond pyramid Indentor (included angle 1360 )

d2

d1

Top view of indentation

Material Testing lab Manual

Department of Industrial Engineering and Management, R.V. College of Engineering, Bangalore 59.

PROCEDURE:1. Place the polished specimen on the platform 2. Raise the platform till the surface of the specimen is focused on the microscope screen. 3. Select the load by pressing the load selector button 4. Load , P = 30 Kg, For ferrous materials 5. = 20 Kg. For non-ferrous materials 6. Wait till the handle on the left side of the frame comes to rest position, and after that allow the load to act for 15 seconds for ferrous materials and 30 seconds for non-ferrous materials 7. Press the handle down without any jerk to release the load and to bring the objective lens back into the position 8. Measure the length of the diagonals (d1 and d2) using the traveling micrometer and calculate their average, d. 9. For each material make at least three indentations and measure the length of the diagonals 10. Using the formula, calculate the Vickers hardness number for each trial and calculate their average. TABULATION AND CALCULATIONS MATERIAL Load Length of diagonal (mm) (Kg) d1 d2 d=(d1+d2) / 2 BRASS 20 0.500 0.500 0.486 0.569 0.553 0.558 0.541 0.530 0.544 0.618 0.610 0.625 0.500 0.476 0.500 0.547 0.547 0.548 0.559 0.516 0.539 0.618 0.620 0.613 0.500 0.488 0.493 0.558 0.550 0.553 0.550 0.523 0.542 0.618 0.615 0.619

Sl. No. 1

VHN X106 N/m2 1455.02 1527.46 1496.65 1168.26 1202.49 1189.48 1803.74 1994.79 1857.38 1428.64 1442.61 1424.03

Average VHNX106 N/m2 1493.04

2

COPPER

20

1186.74

3

CAST IRON

30

1885.3

4

MILD STEEL

30

1431.76

SPECIMEN CALCULATION

Material Testing lab Manual

Department of Industrial Engineering and Management, R.V. College of Engineering, Bangalore 59.

Material : Brass Load,P = 20 Kg = 20 x 9.81 N = 196. 2 N For Trial 1, Length of diagonals, d1 = 0.500 mm & d2 = 0.500 mm Average length of diagonal, d = (d1 +d2)/2 = (0.500 +0.500)/2 = 0.500 mm = 0.500 x 10- 3 m VHN1 = (18.188 x 20)/ (0.500 x 10- 3 ) 2 = 1455.02 x 106 N/m2 VHN2 = (18.188 x 20)/ (0.488 x 10- 3 ) 2 = 1527.46 x 106 N/m2 VHN3 = (18.188 x 20)/ (0.493 x 10- 3 ) 2 = 1496.65 x 106 N/m2 Average VHN = (VHN1+VHN2+VHN3) / 3 = {(1496.63+1455.02 +1455.02) x 106} / 3 N/m2 = 1493.04 x 106 N/m2 RESULTS:MATERIAL COPPER BRASS CAST IRON MILD STEEL VICKERS HARNESS NUMBER (x106 N/M2) 1186.74 1493.04 1885.30 1431.76

2000 1800 1600 1400 1200 1000 800 600 400 200 0

1885.3 1493.04 1186.74 1431.76

Vickers Hardness No.

COPPER

BRASS

CAST IRON

MILD STEEL

Materials

EXPERIMENT No. MT07Material Testing lab Manual

Department of Industrial Engineering and Management, R.V. College of Engineering, Bangalore 59.

COMPRESSION TESTAIM: To study the behaviour of the given materials under compressive loading and to determine the following properties: 1. Maximum Compressive strength, 2. Proportional limit, 3. Elastic limit (Youngs modulus) APPARATUS/EQUIPMENT/INSTRUMENTS USED Universal testing machine, Vernier Caliper, Compression shackles.

Universal Testing Machine

Material Testing lab Manual

Department of Industrial Engineering and Management, R.V. College of Engineering, Bangalore 59.

R.V. COLLEGE OF ENGINEERING, BANGALORE-560059 DEPARTMENT OF INDUSTRIAL ENGG. AND MANAGEMENT MATERIAL TESTING LABORATORY OBSERVATION / DATA SHEET Date: Lab : MT Lab Name: Class: III Sem USN: Expt.No:

Title of the Experiment: COMPRESSION TEST OBSERVATIONS: Least count of Vernier Caliper =0.02mm TABULATION

SL. NO. 1 . 2 . 3 . 4 .

CHARACTERISTIC OF THE SPECIMEN

MATERIAL BRASS 22.00 MILD STEEL 21.16

Initial Height of the specimen (hi) mm 18.00 Initial Diameter of the specimen (di) mm 16.78 Final Height of the specimen (hf) mm Final Diameter of the specimen (df) mm 21.60 22.60 14.70 18.40

Material Testing lab Manual

Department of Industrial Engineering and Management, R.V. College of Engineering, Bangalore 59.

Signature of the staff in charge

TABULATION: INITIAL SCALE READING = 100 mm SL. NO 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 MATERIAL : MILD STEEL LOAD SCALE (KG) READING (mm) 0 1000 2000 3000 4000 5000 6000 7000 8000 9000 14000 15000 16000 17000 18000 19000 20000 21000 22000 23000 24000 25000 14000 15000 100 101 101 101 101 101 101 101 101 101 102 103 104 104 105 105 106 106 106 106 107 108 102 103 SL. NO 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. MATERIAL : BRASS LOAD (KG) SCALE READING (mm) 0 10.0 1000 10.0 2000 10.0 3000 10.0 4000 10.0 5000 10.0 6000 10.0 7000 10.0 8000 100 9000 101 10000 101 11000 101 12000 101 13000 101 14000 101 15000 102 16000 103 17000 103 18000 103 19000 104 20000 104 21000 104 22000 104 23000 105 24000 105 25000 105

Material Testing lab Manual

Department of Industrial Engineering and Management, R.V. College of Engineering, Bangalore 59.

27. 28. 29.

26000 27000 28000

106 106 106

PROCEDURE : 1. Fix the lower and upper compression plates in between the bottom cross head and intermediate crosshead. 2. Measure the initial diameter (di) and initial height (hi) of the given specimen using vernier caliper. 3. Place the specimen at the centre of the bottom plate and bring the top of the specimen in contact with the top plate by moving the intermediate cross head down wards. 4. Apply compressive load in steps of 1000 Kg. 5. The experiment is continued till the specimen attains a barrel shape on reaching the max load for ductile materials or fractures at maximum load for brittle materials. 6. 6.Record load values and corresponding decrease in heights form the scale which is fixed to the UTM. 7. Measure final height (hf ) and largest diameter of the specimen (df) using vernier caliper 8. Calculate stress and corresponding strain. 9. Plot the stress- strain diagram . 10. Calculate the youngs modulus from the graph ( Slope of the graph with in elastic limits) MATERIAL : BRASS INITIAL SCALE READING = 100 mm , A= 254.47mm2 SL NO 1 2 3 4 5 6 7 8 LOAD (Kg) 0 1000 2000 3000 4000 5000 6000 7000 SCALE READING (mm) 100 100 100 100 100 100 100 100 STRESS x106(N/m2) 0 38.55 77.10 115.65 154.20 192.75 231.30 269.85 STRAIN 0 0 0 0 0 0 0 0

Material Testing lab Manual

Department of Industrial Engineering and Management, R.V. College of Engineering, Bangalore 59.

9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29

8000 9000 10000 11000 12000 13000 14000 15000 16000 17000 18000 19000 20000 21000 22000 23000 24000 25000 26000 27000 28000

100 101 101 101 101 101 101 102 103 103 103 104 104 104 104 105 105 105 106 106 106

308.41 346.96 385.51 424.06 462.61 501.16 539.71 578.26 616.81 655.36 693.91 732.46 771.01 809.56 848.12 886.67 925.22 963.77 1002.32 1040.87 1079.42

0 0.045 0.045 0.045 0.045 0.045 0.045 0.091 0.136 0.136 0.136 0.182 0.182 0.182 0.182 0.227 0.227 0.227 0.273 0.273 0.273

MATERIAL: MILD STEEL INITIAL SCALE READING :SL NO 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 LOAD (Kg) 0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000 11000 12000 13000 14000 15000 16000 SCALE READING (mm) 100 100 100 100 100 100 100 100 100 101 101 101 101 101 101 102 103 STRESS x106(N/m2) 0 38.55 77.10 115.65 154.20 192.75 231.30 269.85 308.41 346.96 385.51 424.06 462.61 501.16 539.71 578.26 616.81 STRAIN 0 0 0 0 0 0 0 0 0 0.045 0.045 0.045 0.045 0.045 0.045 0.091 0.136

Material Testing lab Manual

Department of Industrial Engineering and Management, R.V. College of Engineering, Bangalore 59.

18 19 20 21 22 23 24 25 26 27 28 29

17000 18000 19000 20000 21000 22000 23000 24000 25000 26000 27000 28000

103 103 104 104 104 104 105 105 105 106 106 106

655.36 693.91 732.46 771.01 809.56 848.12 886.67 925.22 963.77 1002.32 1040.87 1079.42

0.136 0.136 0.182 0.182 0.182 0.182 0.227 0.227 0.227 0.273 0.273 0.273

Material Testing lab Manual

Department of Industrial Engineering and Management, R.V. College of Engineering, Bangalore 59.

SPECIMEN CALCULATION Material: Brass (Sl.No.2) 1.Stress = P/A = Load in Kgs x 9.81 / Initial Area 2.Initial Area (Ai) = di2/4 = x (18.00)2/4 = 254.47 mm2 = 245.47 x 10-6 m2 3.Stress = 1000 x 9.81 / (245.47 x 10-6) = 38.55 x 106 N/m2 4.Change in Height = Scale reading Initial Scale reading = 100 100 = 0mm 5.Strain = Change in Height / Original Height = 0/ 21.16 = 0.00 6.Final area (Af) = df2/4 = x (21.6)2/4 = 401.15 mm2 = 388.15 x 10-6 m2 7. % increase in area = (Af Ai) x 100 / Ai = 44.00 8. % decrease in height = (hf hi) x 100 / hi = 23.73 9. Compressive Strength = Max. Load / Initial Area = 28000 x 9.81/ (245.47 x 10-6) = 10.79 x 108 N/m2 10. Modulus of elasticity (from graph) = 10.33 x 109 N/m2 SPECIMEN CALCULATION B. Material: Mild Steel (For l.No.2) 1.Stress = P/A = Load in Kgs x 9.81 / Area 2.Initial Area (Ai) = di2/4 = x (18.00)2/4 = 254.47 mm2 = 245.47 x 10-6 m2 3.Stress = 1000 x 9.81 / (245.47 x 10-6) = 38.55 x 106 N/m2 4.Change in Height = Scale reading Initial Scale reading = 101 100 = 1mm

Material Testing lab Manual

Department of Industrial Engineering and Management, R.V. College of Engineering, Bangalore 59.

5. Strain = Change in Height / Original Height = 1/ 21.16 = 0.047 6. Final area (Af) = df2/4 = x (22.6)2/4 = 401.15 mm2 = 401.15 x 10-6 m2 7. 8. 9. % increase in area = (Af Ai) x 100 / Ai = 57.64 % decrease in height = (hf hi) x 100 / hi = 30.53 Maximum Compressive Strength = Max. Load / Initial Area = 25000 x 9.81/ (245.47 x 10-6) = 9.64 x 108 N/m2 Modulus of elasticity (from graph) = 5.67 x 109 N/m2 SPECIMEN SKETCH MATERIAL :DUCTILE BEFORE TESTING MATERIAL :BRITTLE BEFORE TESTING

10.

AFTER TESTING

AFTER TESTING

Material Testing lab Manual

Department of Industrial Engineering and Management, R.V. College of Engineering, Bangalore 59.

STRESS vs STRAIN GRAPH FOR BRASS MATERIAL

RESULT SL. NO. PARAMETER BRASS MILD S T E E L Decrease in height (%) Increase in area (%) Compressive strength ( N/m2) Modules of elasticity (N/m2) 23.73 44.00 10.7942x108 1.033x109 30.53 57.64 96.377x108 5.67x109

1. 2 3 4

Material Testing lab Manual

Department of Industrial Engineering and Management, R.V. College of Engineering, Bangalore 59.

EXPERIMENT No.S01&S02 PREPARATION OF SPECIMEN FOR METALLOGRAPHIC EXAMINATION & MICROSTRUCTURE STUDY OF THE ENGINEERING MATERIALS Objective: To study the microstructure of the given specimen (micro-section) and to determine the grain size. Apparatus: Hand press, flat file, emery papers of various grades, rotary polishing machine and metallurgical microscope. Theory: Micrography is the study of the structures of metals and their alloys under a microscope at magnification from x75 to x1500. The observed structure is called the microstructure. The metallographic studies include; 1. 2. 3. 4. 5. Determination of size and shape of the crystallites, which constitute an alloy. Reveal the structure characteristic of certain type of mechanical working operations. Detect the micro-defects such as nonmetallic inclusions, micro cracks, etc. Determine the chemical content of alloy. It indicates the quality of heat treatment.

Preparation of specimens for microscopical examination: The various steps involved in preparing a specimen for microscopic examination are given below. 1. Selection of specimen: When investigating the properties of a metal, it is essential that the specimen must be homogeneous in composition and crystal structure. A specimen of 10mm diameter or 10mm square is cut from the metal with a saw or water-cooled slitting wheel. The thickness of the specimen should not be more than 12mm. When a specimen is so small that it is difficult to hold, the specimen may be mounted in a suitable compound like thermoplastic resin, by using a hand press. In cases where neither pressure nor heating is desirable, a cold setting thermoplastic resin can be cast round the specimen, a specimen whose surface has been prepared for micro analyses is called micro-section. 2. Grinding: It is primarily necessary to obtain a reasonably flat surface of the specimen. This can be achieved either by using a fairly coarse file or by using motor-driven emery belt. Care must be taken to avoid overheating of the specimen by rapid grinding methods; since this may lead to alterations in the microstructure. When the original hacksaw marks have been ground out, the specimen should be thoroughly washed. 3. Fine grinding: Fine grinding is carried out on waterproof emery papers of progressively finer grades (220, 320, 400 and 600) that are attached to a plane glass plate. The specimen is drawn back and forth along the entire length of No. 220 paper, so that scratches produced are roughly at right angles to those produced by the preliminary grinding operation. Having removed the primary grinding marks, the specimen is washed thoroughly. Grinding is then continued on No. 320 paper and again turning the specimen through 900 until the previous scratch marks has been removed.Material Testing lab Manual

Department of Industrial Engineering and Management, R.V. College of Engineering, Bangalore 59.

This process is repeated with No. 400 and No. 600 papers. Light pressure should be used at all stages. 4. Polishing: The final polishing operation is to remove the fine scratches on the surface by using a rotary polishing machine. The specimen is polished by rubbing it on a soft moist velvet cloth mounted on a flat rotating disc, with the polishing paste. Suitable polishing pastes are fine alumina, magnesia, Chromium oxide or diamond dust. Polishing is continued until a mirror scratch free finish is obtained. Non-ferrous specimens are best finished by hand on a small piece of selvyt cloth wetted with silvo polishing. This should be accomplished with a circular sweep of the hand instead of back and forth motion used in grinding. During polishing a constant trip of water is fed to the rotating pad. After polishing, the specimen must be washed thoroughly. The grease films if any can be removed by immersing the specimen in boiling ethanol. 5. Etching: To make its structure apparent under the microscope, it is necessary to impart unlike appearances to the constituents. This is generally accomplished by selectively corroding or etching the polished surface by applying a chemical etching reagent. Grain boundaries will etch at different rates than the grains, then leaving the grains standing out and they become visible with a reflected light microscope.

Material Testing lab Manual

Department of Industrial Engineering and Management, R.V. College of Engineering, Bangalore 59.

EXPERIMENT No. D03 HEAT TREATMENT OF STEEL MATERIALS & STUDY OF THEIR HARDNESS USING THEIR ROCK-WELL TESTING MACHINE (ANNEALING AND NORMALIZING OF STEEL) Objective: To heat treat the given steel specimen( anneal or normalize)and determine the Rockwell hardness. Apparatus: Austenitizing furnace (upto-1000C) and Rockwell hardness testing machine. Theory: The microstructure of steel part can be modified by heat treatment techniques, that is, by controlled heating and cooling of the alloys at various rates. These treatments induce phase transformations that greatly influence mechanical properties of steel. The various heat-treatment processes are annealing, normalizing, hardening and tempering. Annealing of steel is the process of heating the steel specimen to its austenizing temperature, holding it there long enough to dissolve the cementite and disperse the carbon uniformly and then cool it very slowly to change the structure to the softest state. The low rate of cooling is achieved by turning the furnace off and letting the closed furnace cool down to ambient temperature. The annealing temperature of hypoeutectoid steel is tanneal = Upper critical temperature + 30C to 50C To avoid excessive softness in the annealing of steels, the cooling cycle may be done completely in still air. This process is called normalizing. In normalizing, the part is heated to normalizing temperature and is withdrawn from the furnace. It is then cooled in still air at the room temperature. The more drastically cooled austenite decomposes into a more dispersed aggregate made up of pearlite. After annealing and normalizing, a fine grain structure is obtained, provided there is no super heating. The normalizing temperature is usually 30C to 50C more than that of annealing temperature. The purposes of annealing are: 1. To obtain softness. 2. To improve machinability. 3. To increase ductility and toughness. 4. To relieve internal stresses. 5. To refine the grain size. . 6. To prepare steel for subsequent cold working. The purposes of normalizing the steel are: 1. To eliminate coarse-grained structure obtained in previous working (rolling, forging or stamping). 2. To increase the strength of medium carbon steel. 3. To improve machinability of low carbon steel. 4. To reduce internal stresses.

Material Testing lab Manual

Department of Industrial Engineering and Management, R.V. College of Engineering, Bangalore 59.

Heat-treating furnace: A heat-treating furnace is a refractory lined chamber in which the metal parts are heated to the required temperature. Usually the furnace consists of a box-like structure of steel shell, door, refractory lining. heating source, temperature controls and temperature indicators. Procedure for annealing: 1. Heat the given steel specimen in a box type furnace until the specimen reaches the annealing temperature. 2. keep the specimen in the furnace at the annealing temperature for some time 3. Cool the specimen by switching off the furnace. 4. Remove the steel specimen from the furnace when the furnace is cooled down to atmospheric temperature. 5. Determine the hardness of the annealed specimen using Rockwell hardness testing machine. Procedure for normalizing: 1. Heat the given steel specimen in a box type furnace until the specimen reaches the normalizing temperature. 2. keep the specimen in the furnace at the normalizing temperature for some time 3. Remove the steel specimen from the furnace when the furnace is cooled down to atmospheric temperature. 4. Determine the hardness of the normalized specimen using Rockwell hardness testing machine.

Material Testing lab Manual

Department of Industrial Engineering and Management, R.V. College of Engineering, Bangalore 59.

EXPERIMENT NO. MT05

WEAR TESTAIM: To study the wear properties of the given specimen and to determine the wear rate. APPARATUS/ TOOLS/ EQUIPMENT USED: Wear testing machine Tachometer Scale Digital weighing machine Digital stopwatch.

THEORY: Wear is defined as the progressive loss or removal of material from a surface. Usually parts damaged by wear can be repaired or replaced before disastrous failure takes place. Wear is usually classified as adhesive, abrasive, corrosive, fatigue, fretting, and impact wear. Adhesive wear: If a tangential force is applied between the two sliding blocks, shearing can take place either at the original interface or along a path below or above it, causing adhesive wear. The fracture path depends on whether or not the strength of the adhesive bond of the asperities is greater than the cohesive strength of either of the two sliding bodies. Thus during sliding, fracture at the asperity usually follows a path in the weaker or softer component. A wear fragment is then generated. Although this fragment is attached to the harder component, it eventually becomes detached during further rubbing at the interface and develops into a loose wear particle. This process is known as adhesive wear or sliding wear. Adhesive wear can be reduced by: 1. Selecting materials that do not form strong adhesive bonds. 2. Using a harder material as one of the pair. 3. Using materials that oxidize more easily. Abrasive wear: Abrasive wear is caused by a hard and rough surface sliding across a surface. This type of wears removes particles by forming microchips, thereby producing grooves or scratches on the softer surface. The abrasive wear resistance of metals is directly proportional to their hardness. Abrasive wear can thus be reduced by increasing the hardness of materials or by reducing the normal load. Several methods can be used to observe and measure wear. In general a wear testing machine consists of a means for applying load to a specimen of materials, which is rubbed at a given speed over another piece of material or over an abrasive surface. The amount of wear after a given amount of rubbing is measured either by loss of weight of the specimen or by dimensional changes.

Material Testing lab Manual

Department of Industrial Engineering and Management, R.V. College of Engineering, Bangalore 59.

Wear Testing Machine

The material abrasion wear test machine is used to determine the wear coefficient of hard and soft coating and monolithic materials by abrasive wear in a ball on plate contact configuration. The machine may also be used as a crater generating tool on coated surfaces for coating thickness determination. Test materials are paint films, plastic, coating, shoe material, slurry abrasion. This system can do following wear test: 1. Ball Cratering Test 2. Grinding Process 3. Micro scale Abrasion In general wear testing machine consists of a means for applying load to a specimen of material, which is rubbed at a given speed over another piece of material or over an abrasive surface. The amount of wear after a given amount of rubbing is measured either by loss of weight of specimen or by dimensional changes

Material Testing lab Manual

Department of Industrial Engineering and Management, R.V. College of Engineering, Bangalore 59.

R.V. COLLEGE OF ENGINEERING, BANGALORE-560059 DEPARTMENT OF INDUSTRIAL ENGG. AND MANAGEMENT MATERIAL TESTING LABORATORY OBSERVATION / DATA SHEET Date: Lab : MT Lab Name: Class: III Sem USN: Expt.No:

Title of the Experiment: WEAR TEST OBSERVATIONS: Least count of Vernier Caliper = 0.02mm Radius of wear track in meter (R) = 90mm Speed of the wheel in RPM, (N) = 400 Length of the arm from specimen holder to load point (L1) =300mm Length of the arm from specimen holder to Hanger point (L2) =150mm Sliding time (T) = 10min

TABULATION: Sl. Specimen No Material 1 Aluminium 2 Brass 3 Aluminium 4 Brass

Load, WH (Kg) 1 1 2 2

Weight (gms) Initial (w1) Final (w2) 0.951 0.949 2.411 2.325 0.949 0.946 2.325 1.158

Density, (x103 kg/m3) 2.8 6.8 2.8 6.8

BHN 40 103 40 103

Signature of the staff in charge

PROCEDURE: 1. Clean the surface of the disc and the specimen by alcohol and acetone.

Material Testing lab Manual

Department of Industrial Engineering and Management, R.V. College of Engineering, Bangalore 59.

2. Weigh the specimen in digital weighing machine, measure the length of the arm and the track radius by using scale. Also a note down the length of specimen. 3. Fix the specimen on the horizontal arm using Allen key and place it on the disc. 4. Note down the speed of the disc and switch on the motor. 5. Load the specimen and adjust the displacement sensor to read zero. 6. Switch off the motor after the required interval of time 10 min. 7. The final weight is recorded using digital weighing machine. VH and FS = (Initial weight Final weight) / Density of metal 9. Repeat the above procedure to the other specimen for a given period at constant velocity. Load may also be changed from 1 kg to 2 kg. 10. Repeat the procedure on the other specimens for given load by changing time, speed of the track, track radius, etc. Formulae used:Wear coefficient K = Wear rate = V / S Where V = Volume of wear m3 = Weight loss / Weight loss (Kg) = (W1 W2) / 100 W1 = Initial weight of the specimen (gms) W2 = Final weight of the specimen (gms) = Density of the metal (Kg/m3) H = Hardness of material (B H N) N/m2 VH and FS 8. The wear coefficient and wear rate are calculated by the formulae Wear coefficient K =

Wear rate in debris (mm3), V = Weight loss / Density of metal

L = Normal load (Newton) = W x 9.81 x L1 / L2 W = applied load in Kgs,

Material Testing lab Manual

Department of Industrial Engineering and Management, R.V. College of Engineering, Bangalore 59.

L1 = length of the arm from specimen holder to load point in meter L2 = length of the arm from specimen holder to hanger point in meter S = Sliding distance (meter) = x D x N x T = 2 RNT D = Diameter of wear track in meter R = Radius of wear track in meter N = Speed of the wheel in rpm and T = Sliding time in minutes Wear rate (mm3 / m) = V/S V = Volume of wear in debris in mm3 S = Sliding distance in meter Sl. No 1 2 3 4 Specimen Material Aluminium Brass Aluminium Brass Load, WH (Kg) 1 1 2 2 Weight (gms) Initial Final (w1) (w2) 0.951 0.949 2.411 2.325 0.949 0.946 2.325 1.158 Density, (x103 kg/m3) 2.8 6.8 2.8 6.8 BHN 40 103 40 103 Wear coefficient Kx10-12 2.49 113 1.90 110 Wear rates,mm3/m x10-13 3.0565 4.5845

Specimen Calculation Material Aluminum Least count of Vernier Caliper = 0.01 mm Weight loss = W1 W2 = 0.951 0.949 = 2 x 10-3 gms = 2 x 10-6 Kg Density of the metal, = 2.8 x 104 Kg/m3 Harness of material H = 40 B H N Radius of wear track in meter R = 93 x 10-3 m Speed of the wheel in rpm N = 400 rpm Sliding time T = 10 min Length of the arm from specimen holder to load point, L1 = 360 x 10-3 m Length of the arm from specimen holder to hanger point in meter L2 = 150 x 10-3 m

For trial 1, Load = 1 Kg Initial Weight, W1 = 0.951 gms Final Weight, W2 = 0.949 gms Weight loss = W1 W2 = 0.951 0.949 = 2 x 10-3 gms = 2 x 10-6 Kg

Material Testing lab Manual

Department of Industrial Engineering and Management, R.V. College of Engineering, Bangalore 59.

Volume of material removed =

w1 w2 2 10 6 = 2.8 10 3

(

)

= 7.143 x 10-10 m3 H = 40 W H L 2 1 ( 9.81) 150 mm = 4.905 N Force F = 9.81 = 300 mm L1 Sliding distance = 2RNT = 2 x 93 x 10-3 x 400 x 10 = 2337 m 7.143 10 10 40 Wear coefficient K 1 = = 2.49 10 12 4.905 2337 Wear rate = V / S = 7.143 x 10-10 / 2337 = 3.0565 x 10-13 mm3 / m

Advantages i. High reproducibility ii. Short test time iii. Simple flat test geometry iv. Simple operation Disadvantages i. The tester does not have an arrangement for keeping the air humidity at a constant level. ii. Large variations in humidity might affect the reproducibility. iii. Expensive

Department of Industrial Engineering and Management R.V. College of Engineering, Bangalore 59 VIVA QUESTIONSMaterial Testing lab Manual

Department of Industrial Engineering and Management, R.V. College of Engineering, Bangalore 59.

1. How do you define the word 'Engineering Material? 2. What are the objectives of testing of materials? 3. Write brief classification of materials. 4. List out the properties of materi