NUS Internship Report (2013)_ R K SURAJ

Development of New Magnesium Based

Materials

Using Solidification Route

Submitted By

R K SURAJ

Department of Metallurgical and Materials Engineering,

National Institute of Technology - Trichy, India.

Intern: May – July 2013

DEVELOPMENT OF NEW MAGNESIUM BASED MATERIALS USING SOLIDIFICATION TECHNIQUE

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SUMMARY

Magnesium matrix composites are excellent candidate materials for weight structural application

holding regard to their high specific stiffness, high specific strength, good dimensional stability

and good elevated temperature creep properties. Owing to their inherently low density, good

castability and machinability there has been large interest in Magnesium based alloys due to their

advantages from both the properties as well as the processing counterparts. Thus, this study is to

alloy Magnesium with a material to check for betterment in mechanical properties.

In this study, Pure Magnesium was alloyed with varying concentrations of Fe(powdered form)

using the pathway of Disintegrated Melt Deposition (DMD). For comparison, Pure Magnesium

was also synthesized using DMD technique.

Mechanical Characterization were carried out by conducting tensile, compression, microhardness

and macrohardness tests. The tests revealed an improvement in the 0.2% Yield Strength, Ultimate

Tensile Strength and hardness for 5 wt% Fe.

Fracture surface analysis was carried out on the Tensile fracture surface of the Monolithic Mg and

Composite specimens using the Scanning Electron Microscope (SEM). The fracture surfaces

showed the deformation of Matrix and cleavage type in all the materials analyzed. This indicated

that almost all the materials investigated failed by a predominately mixed mode fracture.


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ACKNOWLEDGEMENT

I would like to take this opportunity to express my heartfelt thanks to my supervisor, Associate

Professor Manoj Gupta, for giving me the opportunity to work under him.

Mr Sankarnarayanan Seetharaman for his invaluable guidance, advice and patience.

Dr Jayalakshmi for her technical guidance and help in casting.

Mr Thoman Tan, lab officer from NUS Materials Science Laboratory for his great effort in

ensuring that facilities were made available and was instrumental in making the project a success.

Sincere thanks to Mr Juraimi, Mr Khalim and Mr Ng Hong Wei from NUS Materials Science

Laboratory for their technical assistance and efforts rendered.

Mr Lam, Mr Rajah from the NUS Fabrication support centre for their technical guidance in

machining the samples for various characterization tests.

Last but not less, sincere appreciations to Mr Pranav, my intern partner for his support.


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TABLE OF CONTENT

SUMMARY…………………………………………………………………2

ACKNOWLEDGEMENT…………………………………………….3

1 INTRODUCTION……………………………………………………..9

2 LITERATURE REVIEW

2.1 INTRODUCTION…………………………………………….......................10

2.2 MATRIX SELECTION……………………………………….......................10

2.3 REINFORCEMENT…………………………………………………………10

2.4 PROCESS TECHNIQUE…………………………………………………….11

2.5 SUMMARY…………………………………………………………..............11

3 MATERIALS AND EXPERIMENTAL PROCEDURES

3.1 MATERIALS………………………………………………………………….12

3.2 PRIMARY PROCESSING……………………………………........................12

3.3 SECONDARY PROCESSING………………………………………………..15

3.4 DENSITY AND POROSITY…………………………………………………15

3.5 MICROSTRUCTURAL CHARACTERISTICS

3.5.1 X-RAY DIFFRACTION……………………………………………………...16

3.5.2 SCANNING ELECTRON MICROSCOPE…………………………………..16

3.6 MECHANICAL CHARACTERISTICS

3.6.1 MICROHARDNESS TEST…………………………………………………...17

3.6.2 MACROHARDNESS TEST……………………………………………..........18

3.6.3 TENSILE TEST………………………………………………………………19

3.6.4 COMPRESSION TEST………………………………………………………21

3.6.5 FRACTOGRAPHY...........................................................................................22


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4 RESULTS

4.1 MATERIAL PROCESSING…………………………………………………..23

4.2 DENSITY AND POROSITY MEASUREMENTS…………………...............23

4.3 DISTRIBUTION OF REINFORCEMENT…………………………...............23

4.4 X-RAY DIFFRACTION……………………………………………………....26

4.5 MICROHARDNESS AND MACROHARDNESS TEST……………………26

4.6 TENSION TEST………………………………………………………………26

4.8 COMPRESSION TEST……………………………………………………….27

4.8 FRACTOGRAPHY…………………………………………………………...27

5 DISCUSSION

5.1 PRIMARY PROCESSING…………………………………………………...32

5.2 SECONDARY PROCESSING……………………………………………….32

5.3 DENSITY AND POROSITY………………………………………………....32

5.4 PARTICLE DISTRIBUTION………………………………………………...33

5.5 MICROHARDNESS………………………………………………………….33

5.6 TENSILE TEST PROPERTIES………………………………………………33

5.7 FRACTOGRAPHY…………………………………………………………...34

6 CONCLUSION………………………………………………………………...35

7 RECOMMENDATIONS……………………………………………………...36

8 REFERRENCES………………………………………………………………37

APPENDIX A: PROCESSING LOG SHEET…………………………………38

APPENDIX B: SETUP FOR DENSITY MEASUREMENT…………………39

APPENDIX C: DENSITY AND POROSITY MEASUREMENT....................40

APPENDIX D: MICROHARDNESS TEST DATA…………….......................42

APPENDIX E: TENSILE SPECIMEN……………………………...................43

APPENDIX F: TENSILE TEST………………………………………………..44


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APPENDIX G: COMPRESSION TEST…………………………...........................................48

APPENDIX H: XRD RESULTS……………………………………………………………....52

LIST OF FIGURES

FIGURE A1: Schematic Methodology………………………………………………………....12

FIGURE B1: Schematic diagram of experimental setup for DMD…………………………….14

FIGURE C1: Sample completely immersed in water during the density measurement………..16

FIGURE D1: JEOL JSM-5600LV Scanning Electron Microscope…………………………….17

FIGURE E1: Indendation being rendered on the specimen……………………………………18

FIGURE E2: Future-Tech Rockwell Type Hardness Tester…………………………………...19

FIGURE F1: The CNC used to machine tensile specimens……………………………………20

FIGURE F2: A view of tensile specimen after machining……………………………………..21

FIGURE F3: A sample undergoing compression test………………………………………….22

FIGURE G1: Representative Optical Micrograph of Mg-5Fe showing distribution of Fe

particles………………………………………………………………………………………….24

FIGURE G2: Representative Optical Micrograph of Mg-15Fe showing distribution of Fe

particles………………………………………………………………………………………….24

FIGURE G3: Representative SEM Micrograph showing void spaces as a result of Fe particles

having left the matrix in Mg-5Fe………………………………………………………………..25

FIGURE G4: Representative SEM Micrograph showing clustering in Mg-15Fe……………...25

FIGURE H1: Macroscopic view of the fractured sample (Mg – 10 Fe) showing increased

ductility………………………………………………………………………………………….28

FIGURE H2: Representative SEM micrograph showing brittle mode fracture of Pure Mg……28

FIGURE H3: Representative SEM micrograph showing mixed mode fracture of Mg+5 Fe…..29

FIGURE H4: Representative SEM micrograph showing mixed mode fracture of Mg+10 Fe....29

FIGURE H5: Representative SEM micrograph showing mixed mode fracture of Mg+15 Fe....30

FIGURE H6: Representative SEM micrograph showing shear bands in Mg 5 Fe……………..30

FIGURE H7: Representative SEM micrograph showing shear bands in Mg 10 Fe……………31

FIGURE H8: Representative SEM micrograph showing shear bands in Mg 15 Fe………........31


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FIGURE I1: Schematic setup of the apparatus used for density measurement………………..39

FIGURE J1 :Tensile Specimen Specification…………………………………………………43 FIGURE K1: Tensile Stress strain curve of Pure Mg…………………………………………44

FIGURE K2: Tensile Stress strain curve of Mg-5Fe …………………………………………45

FIGURE K3: Tensile Stress strain curve of Mg-10Fe………………………………………...46

FIGURE K4: Tensile Stress strain curve of Mg-15Fe………………………………………...47

FIGURE K5: Compression Stress strain curve of Pure Mg…………………………………..48

FIGURE K6: Compression Stress strain curve of Mg-5Fe …………………………………..49

FIGURE K7: Compression Stress strain curve of Mg-10Fe………………………………….50

FIGURE K8: Compression Stress strain curve of Mg-15Fe………………………………….51

FIGURE L1: XRD Plot of Mg-5 Fe…………………………………………………………..52

FIGURE L2: XRD Plot of Mg-5 Fe(As cast)…………………………………………………53

FIGURE L3: XRD Plot of Mg-5 Fe(Transverse Direction)………………………………......54

FIGURE L4: XRD Plot of Mg-10 Fe…………………………………………………………55

FIGURE L5: XRD Plot of Mg-10 Fe(As Cast)…………………………………………….....56

FIGURE L6: XRD Plot of Mg-10 Fe(Transverse Direction)………………………………....57

FIGURE L7: XRD Plot of Mg-15 Fe………………………………………………………….58

FIGURE L8: XRD Plot of Mg-15 Fe(As cast)………………………………………………..59

FIGURE L9: XRD Plot of Mg-15 Fe(Transverse Direction)…………………………………60

LIST OF TABLES

TABLE A1: Tabulation of the yield results…………………………………………………..23

TABLE B1: Tabulation of density and porosity measurements………………………………23

TABLE C1: Tabulation showing results of microhardness and macrohardness……………...26

TABLE D1: Tabulation of tensile testing results……………………………………………..26

TABLE D2: Tabulation of compression test results…………………………………………..27

TABLE E1: Processing log sheet of Mg-5Fe…………………………………………………38

TABLE F1: Summary of calculated theoretical densities…………………………………….40


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TABLE G1: Tabulation of the microhardness values…………………………………………42

TABLE H1: Tensile test results of Pure Mg…………………………………………………..44

TABLE H2: Tensile test results of Mg-5Fe…………………………………………………...45

TABLE H3: Tensile test results of Mg-10Fe………………………………………………….46

TABLE H4: Tensile test results of Mg-15Fe………………………………………………….47

TABLE H5: Compression test results of Pure Mg…………………………………………….48

TABLE H6: Compression test results of Mg-5Fe……………………………………………..49

TABLE H7: Compression test results of Mg-10Fe……………………………………………50

TABLE H8: Compression test results of Mg-15Fe……………………………………………51

TABLE I1: XRD Tabulation of Mg-5Fe………………………………………………………52

TABLE I2: XRD Tabulation of Mg-5Fe(As cast)……………………………………………..53

TABLE I3: XRD Tabulation of Mg-5Fe(Transverse Direction)………………………………54

TABLE I4: XRD Tabulation of Mg-10Fe……………………………………………………..55

TABLE I5: XRD Tabulation of Mg-10Fe(As Cast)…………………………………………...56

TABLE I6: XRD Tabulation of Mg-10Fe(Transverse Direction)……………………………..57

TABLE I7: XRD Tabulation of Mg-15Fe……………………………………………………...58

TABLE I8: XRD Tabulation of Mg-15Fe(As cast)…………………………………………….59

TABLE I9: XRD Tabulation of Mg-15Fe(Transverse Direction)……………………………...60


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1 INTRODUCTION

Increasing demand for materials with superior mechanical properties coupled with low density has

intensified research on Magnesium based composites as candidate materials in satisfying the

demands of serveral industries such as structural, aerospace and automotive sectors.

Metal Matrix Composites have superior mechanical properties in comparison to Pure Magnesium.

Owing to an increase in stiffness and mechanical strength with reinforcements, several advanced

hybrid materials have been developed.

Magnesium is rarely used in its pure form. In view of mechanical property betterment, it is alloyed

commonly with Al, Mn, Zn, Zr, Rare Earth metals and Ag. The major limitation of Magnesium is

low elastic modulus and detrimental properties at elevated service temperatures.

Due to the low cost of processing, research has primarily been in the domain of particulate

reinforcements. Also, particulate reinforced metal matrix composite present ease of fabrication

and display isotropic properties.

Previous studies have shown that additions of Metals such as Ni and Titanium have had profound

impact on improving the Tensile properties of Magnesium.

The Disintegrated Melt Deposition (DMD) technique is a hybrid technique incorporating

conventional melt deposition as well as spray forming. Argon gas jets are utilized to break up the

cast slurry before it forms the mold. The technique is known to give uniform distribution of the

alloying elements coupled with minimal porosity and high yield due to which it has been a growing

area of interest in the synthesis of MMCs.

Several systems of Metal Matrix Composites have been analyzed. However, up to date, very

minimal work has gone into the analysis of reinforcing Magnesium with Iron as a reinforcement.

Though Iron is a tramp element in view of corrosion, there is still hope of strengthening.

Thus the objective of the study is to investigate and compare the properties of Magnesium with

Magnesium-Iron Composite. The composites were synthesized by the Disintegrated Melt

Depoistion (DMD) technique, followed by hot extrusion.

Characterization studies such as density and porosity measurements, x-ray diffraction analysis,

scanning electron microscopy, microhardness, macrohardness, tensile and compressive tests were

carried out on the various composites.


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2 LITERATURE REVIEW

2.1 INTRODUCTION

The focus of researching in a particular domain of materials is mainly done in the interest of

seeking practical application in-view of providing material replacement or in rendering changes

so as to bring about improvements in our daily life. Along similar lines, the main industrial sectors

such as automotive, aerospace and structural have procured interest in choosing Magnesium as a

viable candidate material primarily because of their low density, high specific strength, damping

capacity and other desirable mechanical properties. Further improvement in the properties can be

achieved through incorporation of reinforcements which provide enhanced properties in a

collective sense inclusive of strength, modulus, toughness and ductility. In totality, this is the

reason for focusing research on Mg based metal matrix composite systems.

2.2 MATRIX SELECTION

Among the choice of materials to serve as the matrix, owing to its improved mechanical properties

such as high strength to weight ratio, low density, high damping capacity and other desirable

properties, Magnesium has always been a candidate material. Pertaining to metal matrix

composites, previous studies have shown that Magnesium is effective in binding the reinforcement

and also instrumental in effective load transfer. Also, it has been observed that Magnesium based

composites have been in a position to successfully compete with other monolithic alloys such as

Aluminum, Steel and Titanium for weight-critical applications. These are the reasons for choosing

Magnesium as the matrix material in this study.

2.3 REINFORCEMENT

The major disadvantage with Magnesium is limited formability, low elastic modulus, loss of

strength with increase in temperature and limited ductility at room temperature [10][11]. In order

to improve strength, stiffness in a sense generally improve the mechanical properties,

reinforcements are added to serve the primary purpose of carrying load.

The previous studies have seen considerable increase in mechanical properties by using copper as

a reinforcement[3][4].The ductility of Magnesium has also been improved to considerable levels

by the addition of reinforcements such as Titanium[2]. Also, copper has helped in improving other

mechanical properties of Magnesium such as Elastic modulus and Coefficient of Thermal

expansion[6].The addition of Nickel has shown improvements in mechanical strength as well as

cyclic fatigue life[9]. Hybrid reinforcements comprising of particulate as well as nano additions

within the same composite have shown promising results inview of property betterment [5].


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Niobium addition was found to alter mechanical properties to varying (strength and ductility)

extents based on the amount of Niobium addition[8]. Thus, it is a well established fact that different

reinforcements provide varied responses towards matrix property modification owing to which

there is always a surge to investigate different systems and to characterize the behavior of the

same.

2.4 PROCESSING TECHNIQUE

The end properties of the metal matrix composite have a dependency on the processing technique

used for synthesizing them. Several fabrication techniques are present for MMCs. This includes,

infiltration, pressure deposition, spray deposition, semisolid casting and powder metallurgy. The

matrix and reinforcement also play a role in choosing the processing technique.

The Disintegrated Melt Deposition technique(DMD) is capable of producing MMC castings

having uniform distribution of the reinforcement as well as minimal porosity. This technique

overcomes the disadvantages seen in the case of the spray deposition process and in a parallel

sense maintains low cost. Previous research have made it certain that DMD is capable of

processing good quality MMC castings due to which it has been adopted as the processing pathway

for this system of study.

2.5 SUMMARY

From the literature survey it is clear that the characterization and study of the mechanical responses

have been carried out for a wide domain of metallic reinforcements using Magnesium as the matrix

through the DMD technique. However, no work has been done to incorporate Iron as a

reinforcement. Hence, the motive of this work is to study and characterize the change in

mechanical properties by the synthesis of Mg-Fe MMC.


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3 MATERIALS AND EXPERIMENTAL PROCEDURES

In the present study, majority of the tools and equipment were provided by the Materials Science

Laboratory of the Department of Mechanical Engineering, National University of Singapore. The

raw materials used in the experiments were obtained from various suppliers, and they were

weighed and processed prior to casting via the Disintegrated Melt Deposition method. The

deposited ingots were prepared for extrusion into rods by turning them using a lathe machine. The

extruded rods were then sent for further machining to prepare them for experimentation. An

overview is illustrated in figure

FIGURE A1: Schematic Methodology

3.1 MATERIALS

Magnesium Ingot of 99.8% purity(obtained from Tokyo Magnesium company) were used as the

base matrix material. Fe being selected as the reinforcement particle was obtained from. Holes

were drilled on the ingot and filled with the reinforcement particles after weighing.

3.2 PRIMARY PROCESSING

The synthesis of Pure Mg as well as Mg-Fe(containing 5 wt%, 10 wt% and 15 wt% respectively)

was carried out using the DMD technique.

The position of the stainless steel mold was carefully aligned so that the opening at the top of the

mold was in line with the hole at the bottom of the furnace. Two argon gas jets were connected

near to the opening of the mold so as to disintegrate the melt that was to be flowed through.

A graphite crucible with a centrally drilled hole at its base was used to contain the raw materials

during each casting. A nozzle and a plug, both made of graphite, were machined to conform to the


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size of the hole at the bottom of the crucible. This was to ensure that the melt was contained within

the crucible until it was ready to be deposited into the mold. Two stainless steel foils were used to

secure the plug to the nozzle by keeping the plug in place. A long wire was attached to the screw

on the plug to aid in the pulling out of the plug for the melt to flow down into the mold beneath.

The crucible was subsequently placed into the furnace.

A thermocouple and a mild steel stirrer were placed in position before placing the raw materials

into the crucible. After the raw materials were placed in the crucible, the crucible lid, coated with

a layer of graphite, was then placed onto the crucible, after which a ceramic tube that pumps in

argon gas was inserted to create an inert environment during the casting. Insulating materials were

also placed on top of the furnace to provide an enclosed environment and to minimize extensive

heat loss.

The synthesis procedure involved superheating the raw materials to 750ºC using a CAL-9000

controller unit under an inert atmosphere. The inert atmosphere was provided by an inlet argon gas

jet at constant flow rate of 5 L/min. When the temperature of the melt reaches 750ºC, the melt was

stirred at a uniform speed of approximately 450 rpm for around 5 minutes. The stirring was carried

out using a mild steel twin blade stirrer of 45º pitch, coated with a layer of Zirtex 25 (86% ZrO2,

8.8% Y2O3, 3.6% SiO2, 1.2% K2O and Na2O and 0.3% trace organics) to avoid possible iron

contamination. The stirring was done to facilitate the incorporation of the reinforcement particles

in the Mg matrix with a uniform distribution.

At the end of the 5 minutes of stirring, the melt was allowed to flow through the 10 mm centrally

drilled hole of the nozzle by pulling out the graphite plug. The resultant melt stream was

disintegrated using two linear argon gas jets at a distance of 0.20 m from the melt poring point.

The gas flow rate was maintained at 25 L/min. The disintegrated melt slurry was subsequently

deposited onto a circular metallic substrate located around 0.49 m from the gas disintegrated point.


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FIGURE B1: Schematic diagram of experimental setup for DMD


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3.3 SECONDARY PROCESSING

The ingots obtained from the DMD process were machined down from a diameter of 40 mm to a

diameter of approximately 35 mm using the lathe, of which the ingots were subsequently cut into

billets of around 40 mm in height before they were sent for hot extrusion.

Prior to the hot extrusion process, the billets were soaked in a resistance furnace at a temperature

of 400ºC for an hour. The billets were then hot extruded at a temperature of 350ºC with an

extrusion ratio of 26:1, giving 7 mm diameter rods. Extrusion was performed using a 150 ton

hydraulic press with colloidal graphite as lubricant. After extrusion, the extruded rods were

machined to produce tensile specimens. Short sections of the rods of approximately 10 to 15 mm

in height were cut and cleaned of surface graphite to be used for characterization studies.

3.4 DENSITY AND POROSITY MEASUREMENTS

Density measurements were performed to calculate the experimental density and subsequently the

percentage of porosity in the synthesized materials. The extruded rods were cut into smaller

samples using the Precision Diamond Cutting Machine, and further polished to remove any surface

scales or oxides.

Eight samples of each composition were used to obtain their experimental density using

Archimedes Principle by measuring the dry weight and immersed weight. The samples were

weighed in air and when immersed in distilled water, using an A&D ER-182A electronic balance

with an accuracy of ±0.0001g. Porosities within the samples were subsequently calculated from

the mass fractions of the reinforcements, together with the theoretical and experimental densities

of the synthesized materials.


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FIGURE C1: Sample completely immersed in water during the density measurement

3.5 MICROSTRUCTURAL CHARACTERISTICS

3.5.1 X-RAY DIFFRACTION ANALYSIS

X-ray diffraction analysis was conducted using the automated Shimadzu LAB-X XRD-6000 x-ray

diffractometer. Flat, ground and ultrasonically cleaned specimens of approximately 10 mm in

height were exposed to Cu-Kα radiation (λ = 1.54056 Ǻ) with a scanning speed of 2 °/min. The

scanning range was 30° to 80° for all samples. A plot of intensity against 2θ (θ represents Bragg

angle) was obtained, illustrating peaks at different Bragg angles. The Bragg angles corresponding

to different peaks were noted and the values of interplanar spacing (d-spacing) obtained from the

computerised output were compared with the standard values from the International Centre for

Diffraction Data’s Powder Diffraction File (PDF) .

3.5.2 SCANNING ELECTRON MICROSCOPY

The presence and distribution of the iron particles and possible intermetallic phases was

investigated using the JEOL JSM-5600LV Scanning Electron Microscope (SEM). Polished

specimens were observed at 200x,500x and 1000x magnifications. Images were captured at an

accelerating voltage of 15 kV and spot size of 20. The distribution of the particles were also

observed using the FESEM.


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FIGURE D1: JEOL JSM-5600LV Scanning Electron Microscope.

3.6 MECHANICAL CHARACTERISTICS

The mechanical properties of all samples were characterized by carrying out the tensile,

compression, microhardness and macrohardness tests. All tests were carried out at room

temperature and ambient pressure conditions.

3.6.1 MIRCOHARDNESS TEST

Microhardness measurements were carried out to investigate the influence of the addition of Fe

particles on the microhardness of the Mg matrix. Microhardness measurements were conducted

on extruded specimens polished to 0.3µ-finish using Alumina solution to eliminate scratches and

provide a mirror finish surface coupled with flatness.

The microhardness measurements were conducted using an automatic digital microhardness tester

(Matsuzawa MXT50) with a Vickers indenter (with a square-based pyramidal shaped diamond

indenter with face angles of 136º), 980.7 mN test load and a dwell time of 15 seconds. Testing was

done in accordance with ASTM standards E384-08 and E92-82(2003).


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FIGURE E1: Indendation being rendered on the specimen.

3.6.2 MACROHARDNESS TEST

Macrohardness measurements were carried out to investigate the influence of the addition of Fe

particles on the macrohardness of the Mg matrix.The measurements were conducted on extruded

specimens polished to 0.3µ-finish using Alumina solution to eliminate scratches and provide a

mirror finish surface coupled with flatness.

The superficial hardness tests were conducted using an automatic digital macrohardness

tester(Future-Tech Rockwell Type Hardness tester) with a ball indentor and a load of 15Tonnes.

The values obtained were in Rockwell C scale.


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FIGURE E2: Future-Tech Rockwell Type Hardness Tester

3.6.3 TENSILE TEST

The tensile properties of the extruded monolithic Mg and composites samples were performed in

accordance to ASTM test method E8M-08 [16]. An average of five tensile specimens was obtained

from a single rod, and a minimum of four tensile tests were conducted for each sample. Tensile

tests were conducted on round tensile test specimens of diameter 5 mm and gage length 25 mm

using an automated servohydraulic testing machine (MTS). A digital extensometer was attached

to determine the elongation of the specimen.An initial strain rate of 0.254 mm/min was used. All

test specimens were labeled and packed carefully into individual plastic bags to avoid damages to

the fracture surfaces after the testing, which were used to analyze the mode of fracture for the

fractography analysis.


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From the results of the tensile tests, using the Excel spreadsheet, Stress versus Strain curves were

plotted for all the specimens of monolithic Mg and the composites. Using the offset method, the

0.2% yield strength (0.2% YS) of the specimens was obtained from the graphs. The ultimate tensile

strength (UTS) was also obtained directly from the graphs. Ductility was computed from the

percentage elongation of the original gage length of the test specimens. The work of fracture was

then calculated from the area under the stress-strain curves.

FIGURE F1: The CNC machine used to machine tensile specimens


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FIGURE F2: A view of tensile specimen after machining

3.6.4 COMPRESSION TEST

Compression test was carried out on samples of 8mm length and 8mm diameter with perfectly flat

faces using an automated servohydraulic testing machine (MTS) at a strain rate of 0.8 mm/min.

From the results of the compression tests, using the Excel spreadsheet, Stress versus Strain curves

were plotted for all the specimens of monolithic Mg and the composites. Using the offset method,

the 0.2% yield strength (0.2% YS) of the specimens was obtained from the graphs.


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FIGURE F3: A sample undergoing compression test

3.6.5 FRACTOGRAPHY

The fractured surfaces obtained from the tensile and compression tests were cut from the sample

and immediately studied under the JEOL JSM-5600LV Scanning Electron Microscope to

characterize the mode of failure.


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4 RESULTS

4.1 MATERIAL PROCESSING

A total of 3 castings for the composites and one casting for Monolithic Magnesium were processed using the DMD

technique. The deposited ingots got were weighed for the yield obtained.

Composition Mg (Wt%) Fe (Wt%) Yield (%) Status

Pure Mg 100 0 90.58 PASS Mg – 5 Fe 95 5 61.29 PASS Mg – 10 Fe 90 10 57.97 PASS Mg – 15 Fe 85 15 70.61 PASS

TABLE A1: Tabulation of the yield results

4.2 DENSITY AND POROSITY MEASUREMENTS

Results of density and porosity measurements are summarized below,

Composition Theoretical Density (g/cm3)

Experimental Density (g/cm3)

Porosity (%)

Pure Mg 1.7400 1.7266±0.0004 0.77

Mg – 5Fe 1.8274 1.7363±0.0084 4.98

Mg – 10Fe 1.9264 1.7281±0.0152 10.3

Mg – 15Fe 2.0368 1.7701±0.0326 13.1

TABLE B1: Tabulation of density and porosity measurements

4.3 DISTRIBUTION OF REINFORCEMENT

From the polished specimens, the distribution could be observed. Distribution of Fe in the Mg

matrix formed during the DMD process was found to be good.Fe was distributed in the form of

clusters throughout the matrix and the surface integrity between Fe and Mg was found to be poor

owing to formation of oxide layer.


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FIGURE G1: Representative Optical Micrograph of Mg-5Fe showing distribution of Fe particles.

FIGURE G2: Representative Optical Micrograph of Mg-15Fe showing distribution of Fe particles


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FIGURE G3: Representative SEM Micrograph showing void spaces as a result of Fe particles having left the

matrix in Mg-5Fe

FIGURE G4: Representative SEM Micrograph showing clustering of Fe particles in Mg-15Fe


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4.4 X-RAY DIFFRACTION

The results from the X-Ray Diffraction of the samples were analyzed. The lattice spacings (d-

Spacings) obtained was compared to the standard values for Mg, Fe, Fe-Oxides and MgO. The

results confirmed the presence of Mg in monolithic Mg and the composites. However, Fe was not

detected in the Mg-Fe composites. The tabulation of the XRD results have been presented in the

appendix.

4.5 MICROHARDNESS AND MACROHARDNESS TESTS

Results of microhardness and macrohardness tests performed are summarized in Table. The

composites exhibited higher hardness than Monolithic Mg due to the presence of reinforcements.

However, the hardness value dipped on moving from 5% Fe to 15% Fe additions of reinforcement.

Materials Microhardness (HV 0.1) Macrohardness (HRc)

Pure Mg 42.4 ± 1.8 35 ± 1.3

Mg – 5 Fe 64.4 ± 2.8 49.1 ± 1.2

Mg – 15 Fe 49.4 ± 3.2 41.2 ± 1.3

TABLE C1: Tabulation showing results of microhardness and macrohardness

4.6 TENSILE TEST

The summary of the tensile test results are provided in table. The composites showed improved

0.2% Yield Strength (YS) and UTS but coupled with a reduced ductility for 5% Fe and 15% Fe

additions.

Materials 0.2%YS UTS DUCTILITY(%) WOF (MJ/m3)

Pure Mg 95 ± 9 179± 2 11.7± 0.4 19.9 ± 0.6

Mg – 5 Fe 149 ± 3 215 ± 6 8.9 ± 0.7 18.8 ± 1.8

Mg – 10 Fe 125 ± 2 204 ± 15 16.3 ± 2.4 31.7 ± 2.7

Mg – 15 Fe 129 ± 9 175 ± 15 2.6 ± 0.6 4.8 ± 1.4

WOF: Work of Fracture

TABLE D1: Tabulation of tensile testing results


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4.7 COMPRESSION TEST

The summary of the compression test results are provided in table. The composites showed an

improvement in the 0.2% Yield Strength (YS) and Ultimate Compressive Strength.

Materials 0.2% YS UCS Ductility (%) WOF (MJ/m3)

Pure Mg 45 ± 1 305 ± 5 19.5 ± 7.2 39.3 ± 10.3

Mg – 5 Fe 100 ± 4 403 ± 23 15.1 ± 3.8 45 ± 9.4

Mg – 10 Fe 73 ± 2 310 ± 38 20.3 ± 8.2 41.8 ± 16

Mg – 15 Fe 80 ± 3 322 ± 29 17.1 ± 2.3 37.4 ± 6

WOF: Work of Fracture

TABLE D2: Tabulation of compression test results

4.8 FRACTOGRAPHY

SEM micrographs of the fractured tensile and compression samples were taken at different levels

of magnification to analyze the mode of fracture involved.

The macroscopic examination of the fractured sample of Pure Mg revealed predominately Brittle

type fracture while the composites presented a mixed mode of fracture. The same was further

verified by observing the micrographs in which Pure Mg showed only cleavage facets while the

composites played host to matrix deformation, dimples as well as cleavage facets.

The microscopic examination of the fractured compression samples of Pure Mg as well as

composites revealed large number of shear bands signifying varied extents of work hardening.


28

FIGURE H1: Macroscopic view of the fractured sample (Mg – 10 Fe) showing increased ductility

(Tensile)

FIGURE H2: Representative SEM micrograph showing brittle mode fracture of Pure Mg


29

FIGURE H3: Representative SEM micrograph showing mixed mode fracture of Mg+5 Fe



30


(Compression)

FIGURE H6: Representative SEM micrograph showing shear bands in Mg 5 Fe


31




32

5 DISCUSSION

5.1 PRIMARY PROCESSING

The DMD technique was successfully employed in the casting of monolithic Mg and the

composites. The DMD technique allowed rapid cooling of the composites by disintegrating the

metal stream using two argon gas jets, resulting in fine grain structure. Homogeneity of the melt

was also achieved through the stirring process, resulting in fine and homogeneously distributed

reinforcements.

During the process, care had to be taken so that the mold and the nozzle were properly aligned to

ensure that a sufficiently high deposited yield could be obtained. Some amount of Fe powder was

added using Magnesium tubings which were placed on the top of the ingot. The reinforcement and

the matrix materials were also being placed in alternate layers in the crucible to provide an initial

wetting to a greater amount of reinforcement particles with the matrix material, thus reducing the

particle settling effect. The deposited ingots showed no macropores or blowholes and there was

minimal oxidation of melt and no detectable reaction between the graphite crucible and melt. These

observations are consistent with the previous findings made on DMD processed magnesium based

composites and verified the suitability of DMD as the primary processing method for this study.

No apparent reaction between the melt slurry and the graphite crucible is primarily attributed to

the inability of Mg to form stable carbides.

5.2 SECONDARY PROCESSING

For the extrusion process, an extrusion temperature of 350ºC with a soaking temperature of 400ºC

and a soaking time of 1 hour were applied to the synthesized materials. The extrusion ratio was set

to 20.25:1 to obtain 8 mm rods. These conditions were selected based on previous studies

conducted, indicating that these parameters were suitable for the successful extrusion of monolithic

Mg and composites. Minimal surface damage was observed on all the extruded rods. The outer

surface of the rod was smooth with no visible defects.

5.3 DENSITY AND POROSITY

The density measurements were carried out using eight samples for each composition taken from

different parts of the extruded rod. The low values of standard deviation are indicative of the face

that the reinforcement has more or less a uniform distribution throughout the matrix. An increase

in density was observed in the case of 15% Fe owing to the increased amount of reinforcement


33

value while 5% and 15% Fe showed density close to Monolithic Magnesium for which the possible

reasons include oxidation of Fe and also, reduced amount of Iron impregnation into the matrix

during the casting. Also, all the composites showed increased values of porosity.

5.4 PARTICLE DISTRIBUTION

The FESEM micrographs revealed uniform distribution of particles. A high degree of clustering

was noted along with wide spacing between the reinforcement clusters.

The uniform distribution of reinforcements and intermetallic phases could be a result of

appropriate choice of stirring parameters leading to a fair distribution in the composites and the

redistribution during extrusion as a result of different deformation modes in operation. Good

compatibility of the reinforcement particles with Mg, resulting in better incorporation of the

reinforcement particles into the Mg matrix, could also be the reason for the uniform distribution.

Thus the improved strength of composites in comparison to Monolithic Magnesium can be

attributed to the uniform distribution as observed on the micrograph.

However, the reinforcement particles showed poor surface integrity with the matrix due to

formation of oxide layer owing to Fe.

5.5 MICROHARDNESS

Hardness is defined as the resistance offered by the material to penetration. As the results suggest,

the composites showed higher values of both microhardness as well as macrohardness owing to

the uniform distribution of the reinforcement throughout the matrix. These reinforcements are hard

phases and thus lead to increased resistance to penetration consequently resulting in higher values

of hardness. Similar improvement in microhardness was observed with the addition of Copper

particulates to Magnesium [4].

5.6 TENSILE TEST PROPERTIES

The results in the tensile test showed an improvement in the 0.2% yield strength and ultimate

tensile strength of Pure Magnesium with increasing additions of Fe. This can be attributed to

effective transfer of applied load to the presence of well bonded reinforcements in the matrix. In

general improvement in strength was noted for all three composites. However, the best 0.2% YS

and ultimate tensile strength was observed in Mg-5 wt% Fe composite with 47% and 15% increase

respectively. The decreases in the level of improvement of these properties can be attributed to an

increase in the level of clustering.


34

The characterizations revealed an improvement in the ductility only for Mg-10 wt% Fe composite

which can be related to the deformation of ductile Iron particles by means of load transfer from

the matrix thereby delaying the process of fracture and resulting in increased ductility. Similar

observations of an increase in ductility was noted with Titanium[2]. The drastic drop in ductility

associated with Mg – 15 wt% Fe can be correlated with the high level of clustering which might

serve as crack nucleation sites leading to a reduction in ductility during tensile testing.

Work of fracture is defined as the ability of the material to absorb energy before failure under an

applied load. An improvement of 53% in the work of fracture pertaining to Mg – 10 wt% Fe

composite corresponds to the higher ductility presented by the same.

5.7 FRACTOGRAPHY

Macroscopic examination of the fractured tensile specimens showed mixed mode of failure. The

same was seen in the case of SEM micrographs in which the system presented cleavage facets as

well as dimples. Mg-10 wt% Fe showed increased levels of river-like dimples which is

complemented by its comparatively high ductility. Pure Mg however presented predominately

cleavage facets which indicates the inability of Mg to cleave on any single plane. Microcracks

were present predominately in all compositions which is the reason for reduced failure strain.

The compression micrograph in all specimens showed work hardened regions. These were

represented by the presence of shear bands. In the case of compression, during loading, the

reinforcement particles move away from the matrix due to which the properties are reflected by

the behavior of the matrix only. As a result, the various micrographs of the compression samples

showed a similar trend for all compositions.


35

6 CONCLUSION

The following are the conclusions that can be drawn from the characterizations carried out on the

systems in this study:

1) Magnesium based composites containing Iron particles can be successfully synthesized by

using the disintegrated melt deposition technique followed by hot extrusion.

2) The SEM micrographs of the various composites showed the presence of reinforcement

clustering with uniform distribution in the matrix.

3) Tensile property characterizations revealed an improvement in the 0.2% YS and UTS for

all compositions. Enhancement in ductility was observed only in the case of Mg-10 wt%

Fe while it was reduced in the other composites.

4) The hardness of Magnesium was enhanced by the addition of Fe as a reinforcement owing

to the distribution of the hard alloying reinforcements.

5) The composites showed a mixed mode of failure by presenting both cleavage facets as well

as river-like dimples in the micrograph.

6) Analysis of the compression fractured samples showed varied levels of work hardening at

different regions within the same sample for all concentrations.


36

7 RECOMMENDATIONS

The following are suggestions that could be addressed to improve the results of this study:

1) The reinforcement used in this study was Iron which is a tramp element in view of

Corrosion. Along with Iron, further alloying additions pertaining to corrosion promoters

can be made to investigate the properties and correlate with reinforcements’ susceptibility

to corrosion.

2) The system can be heat treated to investigate the possibility of further increase in

mechanical properties.


37

8 REFERENCES

[1] S. Jayalakshmi, Q.B. Nguyen, M. Gupta, Microstructural and mechanical properties of AZ31

magnesium alloy with Cr addition and CO2 incorporation during processing, Department of

Mechanical Engineering, National University of Singapore (NUS), 9 Engineering Drive 1,

Singapore 117576, Singapore.

[2] Hassan, S.F. and M. Gupta, Development of ductile magnesium composite materials using

titanium as reinforcement. Journal of Alloys and Compounds, 2002.

[3] K.F. Ho, M. Gupta T.S. Srivatsan , The mechanical behavior of magnesium alloy AZ91

reinforced with fine copper particulates, Journal of Materials Science and Engineering.

[4] Hassan, S.F and M.Gupta, Development of a novel magnesium-copper based composite with

improved mechanical properties. Department of Mechanical Engineering, National University of

Singapore (NUS), 9 Engineering Drive 1, Singapore 117576, Singapore.

[5] S. Sankaranarayanan, R.K. Sabat, S. Jayalakshmi, S. Suwas, M. Gupta, Effect of hybridizing

micron-sized Ti with nano-sized SiC on the microstructural evolution and mechanical response of

Mg–5.6Ti composite. Department of Mechanical Engineering, National University of Singapore

(NUS), 9 Engineering Drive 1, Singapore 117 576, Singapore,Department of Materials

Engineering, Indian Institute of Science, Bangalore 560 012, India.

[6] S.F. Hassan, K.F. Ho, M. Gupta, Increasing elastic modulus, strength and CTE of AZ91 by

reinforcing pure magnesium with elemental copper. Department of Mechanical Engineering,

National University of Singapore (NUS), 9 Engineering Drive 1, Singapore 117 576, Singapore.

[7] S. Jayalakshmi, S. Sankaranarayanan, S.P.X. Koh, M. Gupta, Effect of Ag and Cu trace

additions on the microstructural evolution

and mechanical properties of Mg–5Sn alloy, Department of Mechanical Engineering, National

University of Singapore (NUS), 9 Engineering Drive 1, Singapore 117 576, Singapore.

[8] M. Shanthi,, P. Jayaramanavar, V. Vyas, D.V.S. Seenivasan, M. Gupta, Effect of niobium

particulate addition on the microstructure and mechanical properties of pure magnesium.Journal

of Alloys and Compounds.

[9] S.F.Hassan, M.Gupta, Development of a novel magnesium/ nickel composite with improved

mechanical properties, Journal of Alloys and Compounds.

[10] D.J. Towle, C.M. Friend, Mater. Sci. Eng. A 188 (1994) 153. [11] A. Martin, J.L. Lorca,

Mater. Sci. Eng. A 201 (1995) 77.


38

APPENDIX A : PROCESSING LOG SHEET

Experiment No. 1 20 May 2013

MMC System Mg 5 Fe Pass

Processing Route Disintegrated Melt Deposition (DMD) Technique

Heating Profile: Temperature (°C) vs Time (mins)

RAW MATERIALS

Matrix Initial Mass (g) Form Purity

Mg 716 Billet 99.9+ %

REINFORCEMENTS

Type 1 Fe Type 2 -

Form Powder Form -

Mass (g) 58 Mass (g) -

Wt % 5 Wt % -

Mode of Addition Layered

HEATING TEMPERATURE

Starting Time 1030 Ending Time 1210

Initial Temperature 28 °C Final Temperature 750 °C

APPARATUS

Crucible Type Graphite Impeller Type Mild Steel, Twin

Blade, Pitch 45° Crucible Size A12

Crucible Diameter 125 mm

Impeller Diameter

75 mm Nozzle Size 10 mm

STIRRING CONDITIONS

Stirring Temp. 750 °C Stirrer Position Stirring Time 8mins

15 mm from bottom of crucible Stirring Speed 450 rpm

ARGON SUPPLY

Gas flow rate to crucible 2.5 L/min Gas flow rate to mould 25 L/min

PROCESS PERCENTAGE YIELD

Initial Mass (g) 775

Deposited Mass (g) 475 % Yield (Deposited) 61.29

TABLE E1: Processing log sheet of Mg-5Fe

0

200

400

600

800

0 20 40 60 80 100 120


39

APPENDIX B: SCHEMATIC SETUP OF APPARATUS FOR

DENSITY MEASUREMENT

FIGURE I1: Schematic setup of the apparatus used for density measurement


40

APPENDIX C: DENSITY AND POROSITY MEASUREMENTS

Using the symbols defined earlier in table ,the total volume of the composite is given by,

𝑉𝐶 = 𝑉𝑀𝑔 + 𝑉𝐹𝑒

⟹𝑊𝐶

𝜌𝐶=

𝑊𝑀𝑔

𝜌𝑀𝑔+

𝑊𝐹𝑒

𝜌𝐹𝑒

Thus, the expression for theoretical density of the composite is given by,

𝜌𝑇ℎ𝑒𝑜𝑟𝑒𝑡𝑖𝑐𝑎𝑙 =1

(𝑊𝑀𝑔

𝜌𝑀𝑔+

𝑊𝐹𝑒

𝜌𝐹𝑒)

SAMPLE CALCULATION

Sample calculation will be based on Mg-15 Fe composition.

𝜌𝑇ℎ𝑒𝑜𝑟𝑒𝑡𝑖𝑐𝑎𝑙 =1

(0.85

1.738+

0.015

7.874) = 2.0367 g/cm3

The table below summarizes the calculated theoretical densities,

Composition Mg (Wt%) Fe (Wt%) Theoretical Density (g/cm3)

Mg – 5 Fe 95 5 1.8273

Mg – 10 Fe 90 10 1.9263

Mg – 15 Fe 85 15 2.0361

TABLE F1: Summary of calculated theoretical densities

CALCULATION FOR EXPERIMENTAL DENSITY

The expression for experimental density is given by,

𝜌𝑒𝑥𝑝 =𝑊𝑎𝑖𝑟𝜌𝑤𝑎𝑡𝑒𝑟 − 𝑊𝑤𝑎𝑡𝑒𝑟𝜌𝑎𝑖𝑟

𝑊𝑎𝑖𝑟 − 𝑊𝑤𝑎𝑡𝑒𝑟


41

Where 𝑊𝑎𝑖𝑟 and 𝑊𝑤𝑎𝑡𝑒𝑟 are the weight of specimen in air and water, measured in grams

respectively; 𝜌𝑎𝑖𝑟 and 𝜌𝑤𝑎𝑡𝑒𝑟 are the density of air (0.001225 g/cm3) and water (1 g/cm3)

respectively.

SAMPLE CALCULATION

The following calculation will be based on the composite Mg-15Fe (Specimen 1),

𝜌𝑒𝑥𝑝 =0.6147 𝑥 1−0.2671 𝑥 0.001225

0.6147−0.2671= 1.7676 gm/cm3

POROSITY CALCULATION

The expression for calculating porosity is given by,

𝑃𝑜𝑟𝑜𝑠𝑖𝑡𝑦 =𝜌𝑡ℎ𝑒𝑜 − 𝜌𝑒𝑥𝑝

𝜌𝑡ℎ𝑒𝑜 − 𝜌𝑎𝑖𝑟

SAMPLE CALCULATION

The following calculation will be based on the composite Mg-15 Fe(Specimen 1),

𝑃𝑜𝑟𝑜𝑠𝑖𝑡𝑦 =2.0367 − 1.7676

2.0367 − 0.001225= 13.22%


42

APPENDIX D: MICROHARDNESS TEST RAW DATA

The following were the microhardness values obtained for the samples tested:

COMPOSITION 1 2 3 4 5 6 7 8 9 10 11 12 Mean Standard Deviation

Pure Mg 44.7 44.3 42.6 41.6 41.6 44.4 44.3 40.4 42.4 40.6 42.8 39 42.39167 1.82879

Mg – 5 Fe 68.7 62.3 61.9 64.3 69.3 64.1 66.0 65.1 60.2 65.0 61.3 64 64.35 2.76422

Mg – 15 Fe 48.5 48.8 55.1 48.0 47.2 50.7 51.9 50.0 53.1 49.6 42.6 47.7 49.4333 3.18529

TABLE G1: Tabulation of the microhardness values


43

APPENDIX E: TENSILE SPECIMEN

Figure J1 : Tensile Specimen Specification

Dimensions and Tolerances:

G – Gauge length : 25.0 ± 0.1 mm

D – Diameter1 : 5.0 ± 0.1 mm

R – Radius of fillet : 5.0

A – Length of reduced section : 30


44

APPENDIX F: TENSILE TEST

FIGURE K1: Tensile Stress strain curve of Pure Mg

Specimen No. 0.2 % YS UTS(MPa) Failure Strain(%) WOF (MJ/m3)

1 96 181 11.4 19.5

2 94 178 12 20.4

3 201 201 11.5 22

TABLE H1: Tensile test results of Pure Mg

0

20

40

60

80

100

120

140

160

180

200

0.00% 2.00% 4.00% 6.00% 8.00% 10.00% 12.00% 14.00%

Spec1

Spec2


45

FIGURE K2: Tensile Stress strain curve of Mg-5Fe


1 149 215 8.3 17.5

2 152 220 9.7 20.9

3 146 208 8.8 17.9

4 164 246 6.8 16.5

5 157 235 7.2 16.6

TABLE H2: Tensile test results of Mg-5Fe

0

50

100

150

200

250

0.00% 2.00% 4.00% 6.00% 8.00% 10.00% 12.00%

Spec1

Spec2

Spec3


46

FIGURE K3: Tensile Stress strain curve of Mg-10 Fe


1 126 189 18.8 34.3

2 123 205 16.4 31.8

3 108 196 16.2 30.1

4 112 200 18.8 35.4

5 121 222 1.8 29

6 127 218 13.9 28.9


0

50

100

150

200

250

0.00% 5.00% 10.00% 15.00% 20.00% 25.00%

Spec1Spec2Spec6


47

FIGURE K4: Tensile Stress strain curve of Mg-15 Fe


1 131 173 2.3 4.2

2 138 190 3.3 6.4

3 120 161 2.3 3.8


0

20

40

60

80

100

120

140

160

180

200

-0.50% 0.00% 0.50% 1.00% 1.50% 2.00% 2.50% 3.00% 3.50% 4.00% 4.50%

Spec1

Spec2

Spec3


48

APPENDIX G: COMPRESSION TEST

FIGURE K5: Compression Stress strain curve of Pure Mg

Specimen No. 0.2 % YS UCS(MPa) Failure Strain(%) WOF (MJ/m3)

1 44 309 22.6 41.2

2 46 300 11.2 25.2

3 36 312 21.3 42.3

4 53 314 23.2 62.4

5 68 315 21 46.6

6 45 306 24.5 48.5

TABLE H5: Compression test results of Pure Mg

0

50

100

150

200

250

300

350

-5.00% 0.00% 5.00% 10.00% 15.00% 20.00% 25.00% 30.00%

Spec1

Spec2

Spec6


49

FIGURE K6: Compression Stress strain curve of Mg-5Fe


1 99 402 19.3 55.8

2 97 381 13.8 38.7

3 112 438 11.6 41

4 104 426 12.1 40.6

5 117 431 8.2 39.2

6 75 363 9.7 31.7

TABLE H6: Compression test results of Mg-5Fe

0

50

100

150

200

250

300

350

400

450

0.00% 5.00% 10.00% 15.00% 20.00% 25.00% 30.00%

Spec1

Spec2

Spec4


50



1 75 339 14.7 39.3

2 49 302 18.3 32.5

3 79 339 18.7 42.3

4 63 289 18.1 30.7

5 72 267 16.6 27.2

6 73 323 29.8 58.8


0

50

100

150

200

250

300

350

400

0.00% 5.00% 10.00% 15.00% 20.00% 25.00% 30.00% 35.00% 40.00%

Spec1

Spec5

Spec6


51



1 79 339 14.5 39.3

2 47 302 18.4 32.5

3 79 339 18.7 42.3

4 83 289 18 30.7

5 72 267 16.6 27.2

6 73 323 29.8 58.8


0

50

100

150

200

250

300

350

400

0.00% 5.00% 10.00% 15.00% 20.00% 25.00%

Spec1

Spec3

Spec4


52

APPENDIX H: XRD RESULTS

FIGURE L1: XRD Plot of Mg-5 Fe

2θ Intensity(dps) 2θ Intensity(dps) 32.18 844 67.28 116 34.42 937 68.68 142

36.64 1162 69.96 308 47.88 159 72.44 25

57.36 288 78.04

63.04 198 TABLE I1: XRD Tabulation of Mg-5Fe


53

FIGURE L2: XRD Plot of Mg-5 Fe(As cast)

2θ Intensity(dps) 2θ Intensity(dps) 32.2 223 67.54 15

34.2 306 68.7 70

36.64 1205 70.06 54 47.86 145 72.6 17

57.42 132 77.84 37 63.08 168

TABLE I2: XRD Tabulation of Mg-5Fe(As cast)


54

FIGURE L3: XRD Plot of Mg-5 Fe(Transverse Direction)

2θ Intensity(dps) 2θ Intensity(dps)

32.2 20 68.62 61 34.49 279 69.92 11

36.66 781 70.02 9 47.84 61 72.5 18

57.36 42 77.2 4

63.06 88 TABLE I3: XRD Tabulation of Mg-5Fe(Transverse Direction)


55



34.38 438 68.58 132

36.6 1149 69.92 309 47.76 152 72.44 36

57.32 365 78 30 63.1 134

TABLE 1I4: XRD Tabulation of Mg-10Fe


56

FIGURE L5: XRD Plot of Mg-10 Fe(As Cast)


32.16 65 67.28 12 34.42 227 68.62 36

36.64 354 70.06 14 47.86 71 72.72 12

57.38 375 77.94 9 63.06 76

TABLE I5: XRD Tabulation of Mg-10Fe(As Cast)


57



32.22 37 67.3 6 34.42 250 68.58 37

36.64 302 70.04 18

47.8 74 72.46 17 57.4 22 77.88 7

63.04 98 TABLE I6: XRD Tabulation of Mg-10Fe(Transverse Direction)


58



34.38 483 68.68 88

36.6 805 69.94 452 47.9 64 72.6 36

57.32 499 77.8 27 63.08 105

TABLE I7: XRD Tabulation of Mg-15Fe


59

FIGURE L8: XRD Plot of Mg-15 Fe(As cast)


34.42 475 68.6 101

36.64 890 70 248 47.8 199 72.4 27

57.3 49 77.99 15 63.02 100

TABLE I8: XRD Tabulation of Mg-15Fe(As cast)


60



34.46 393 68.7 40 36.66 262 70.1 12

47.9 61 72.5 32

57.44 16 77.92 6 63.12 103

TABLE I9: XRD Tabulation of Mg-15Fe(Transverse Direction)


61

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