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Metal –Casting Processes
Source : Manufacturing Processes for Engineering Materials,5Source : Manufacturing Processes for Engineering Materials,5rdrd Edition., S. Kalpakjian and S. Schmid, 2008 , Edition., S. Kalpakjian and S. Schmid, 2008 , Additional references in the last slide
Source : Manufacturing Processes for Engineering Materials,5Source : Manufacturing Processes for Engineering Materials,5rdrd Edition., S. Kalpakjian and S. Schmid, 2008 , Edition., S. Kalpakjian and S. Schmid, 2008 , Additional references in the last slide
Metals processed by casting
Sand casting – 60% Permanent mold casting – 11% Die casting – 9% Investment casting – 7% Centrifugal casting – 7% Shell mold casting – 6%
Source : Manufacturing Processes for Engineering Materials,5Source : Manufacturing Processes for Engineering Materials,5rdrd Edition., S. Kalpakjian and S. Schmid, 2008 , Edition., S. Kalpakjian and S. Schmid, 2008 , Additional references in the last slide
Types of Parts Made
Engine blocks Pipes Jewelry
Source : Manufacturing Processes for Engineering Materials,5Source : Manufacturing Processes for Engineering Materials,5rdrd Edition., S. Kalpakjian and S. Schmid, 2008 , Edition., S. Kalpakjian and S. Schmid, 2008 , Additional references in the last slide
Mold Features
The following is a gravity casting system.2 principles of fluid flow are relevant to gating design:
Bernoulli’s theorem and the law of mass continuity.
Source : Manufacturing Processes for Engineering Materials,5Source : Manufacturing Processes for Engineering Materials,5rdrd Edition., S. Kalpakjian and S. Schmid, 2008 , Edition., S. Kalpakjian and S. Schmid, 2008 , Additional references in the last slide
Source : Manufacturing Processes for Engineering Materials,5Source : Manufacturing Processes for Engineering Materials,5rdrd Edition., S. Kalpakjian and S. Schmid, 2008 , Edition., S. Kalpakjian and S. Schmid, 2008 , Additional references in the last slide
Ferrous casting alloysCast irons represent the largest amount of all metals cast and can cast into complex shapes.
Types of irons:
Gray cast iron Ductile iron (nodular iron) White cast iron Malleable iron Compacted-graphite iron Cast steels Cast stainless steels
Source : Manufacturing Processes for Engineering Materials,5Source : Manufacturing Processes for Engineering Materials,5rdrd Edition., S. Kalpakjian and S. Schmid, 2008 , Edition., S. Kalpakjian and S. Schmid, 2008 , Additional references in the last slide
Nonferrous casting alloys
Types of alloys:
Aluminum-based alloys Magnesium-based alloys Copper-based alloys Zinc-based alloys High-temperature alloys
Source : Manufacturing Processes for Engineering Materials,5Source : Manufacturing Processes for Engineering Materials,5rdrd Edition., S. Kalpakjian and S. Schmid, 2008 , Edition., S. Kalpakjian and S. Schmid, 2008 , Additional references in the last slide
Components of Casting
Path: Sprue -> Well -> Runner -> Mold cavity Riser: Compensate volume loss due to shrinkage Location of riser? Core: Make holes Core print Draft: Prevent collapse
of sand
Source : Manufacturing Processes for Engineering Materials,5Source : Manufacturing Processes for Engineering Materials,5rdrd Edition., S. Kalpakjian and S. Schmid, 2008 , Edition., S. Kalpakjian and S. Schmid, 2008 , Additional references in the last slide
Expendable-Mold Permanent-Pattern Casting Processes
Source : Manufacturing Processes for Engineering Materials,5Source : Manufacturing Processes for Engineering Materials,5rdrd Edition., S. Kalpakjian and S. Schmid, 2008 , Edition., S. Kalpakjian and S. Schmid, 2008 , Additional references in the last slide
Sand Casting
Types of sand molds 3 types: green-sand, cold-box, and no-bake
molds. Green molding sand is mixture of sand, clay, and
water and is inexpensive. In skin-dried method, castings has high strength,
better accuracy and surface finish. In no-bake mold process, a synthetic liquid resin
is mixed with the sand and hardened in room temperature.
Source : Manufacturing Processes for Engineering Materials,5Source : Manufacturing Processes for Engineering Materials,5rdrd Edition., S. Kalpakjian and S. Schmid, 2008 , Edition., S. Kalpakjian and S. Schmid, 2008 , Additional references in the last slide
Sand Casting
Source : Manufacturing Processes for Engineering Materials,5Source : Manufacturing Processes for Engineering Materials,5rdrd Edition., S. Kalpakjian and S. Schmid, 2008 , Edition., S. Kalpakjian and S. Schmid, 2008 , Additional references in the last slide
Source : Manufacturing Processes for Engineering Materials,5Source : Manufacturing Processes for Engineering Materials,5rdrd Edition., S. Kalpakjian and S. Schmid, 2008 , Edition., S. Kalpakjian and S. Schmid, 2008 , Additional references in the last slide
Source : Manufacturing Processes for Engineering Materials,5Source : Manufacturing Processes for Engineering Materials,5rdrd Edition., S. Kalpakjian and S. Schmid, 2008 , Edition., S. Kalpakjian and S. Schmid, 2008 , Additional references in the last slide
Shell-mold casting Can produce castings with close
dimensional tolerances Good surface finish Low cost.
Source : Manufacturing Processes for Engineering Materials,5Source : Manufacturing Processes for Engineering Materials,5rdrd Edition., S. Kalpakjian and S. Schmid, 2008 , Edition., S. Kalpakjian and S. Schmid, 2008 , Additional references in the last slide
Ceramic Mold Manufacture
FIGURE 5.18 Sequence of operations in making a ceramic mold .
Source : Manufacturing Processes for Engineering Materials,5Source : Manufacturing Processes for Engineering Materials,5rdrd Edition., S. Kalpakjian and S. Schmid, 2008 , Edition., S. Kalpakjian and S. Schmid, 2008 , Additional references in the last slide
Description: Green Sand Casting Capabilities
Horacio Elizondo Author
April 2003Date
Alting,Leo. “Manufacturing Processes Reference Guide.” 1994Reference
Shape Material Conserve Material Consolidation Function – Sub function
Source : Manufacturing Processes for Engineering Materials,5Source : Manufacturing Processes for Engineering Materials,5rdrd Edition., S. Kalpakjian and S. Schmid, 2008 , Edition., S. Kalpakjian and S. Schmid, 2008 , Additional references in the last slide
Expendable-Mold ,Expendable-Pattern Casting Processes
Source : Manufacturing Processes for Engineering Materials,5Source : Manufacturing Processes for Engineering Materials,5rdrd Edition., S. Kalpakjian and S. Schmid, 2008 , Edition., S. Kalpakjian and S. Schmid, 2008 , Additional references in the last slide
Expendable-pattern casting (lost foam) Evaporative Pattern Casting
FIGURE 5.20 Schematic illustration of the expendable-pattern casting process, also known as lost-foam or evaporative-pattern casting .
Source : Manufacturing Processes for Engineering Materials,5Source : Manufacturing Processes for Engineering Materials,5rdrd Edition., S. Kalpakjian and S. Schmid, 2008 , Edition., S. Kalpakjian and S. Schmid, 2008 , Additional references in the last slide
Investment Casting (lost-wax process)
Source: Schematic illustration of investment casting (lost wax process). Castings by this method can be made with very fine detail and from a variety of metals. Source: Steel
Founders' Society of America .Source : Manufacturing Processes for Engineering Materials,5Source : Manufacturing Processes for Engineering Materials,5rdrd Edition., S. Kalpakjian and S. Schmid, 2008 , Edition., S. Kalpakjian and S. Schmid, 2008 , Additional references in the last slide
Description: Investment Casting Capabilities
Horacio Elizondo Author
April 2003Date
Alting,Leo. “Manufacturing Processes Reference Guide.” 1994Reference
Shape Material Conserve Material Consolidation Function – Sub function
Source : Manufacturing Processes for Engineering Materials,5Source : Manufacturing Processes for Engineering Materials,5rdrd Edition., S. Kalpakjian and S. Schmid, 2008 , Edition., S. Kalpakjian and S. Schmid, 2008 , Additional references in the last slide
Investment Casting
Source : Manufacturing Processes for Engineering Materials,5Source : Manufacturing Processes for Engineering Materials,5rdrd Edition., S. Kalpakjian and S. Schmid, 2008 , Edition., S. Kalpakjian and S. Schmid, 2008 , Additional references in the last slide
Permanent-Mold Casting Processes
Source : Manufacturing Processes for Engineering Materials,5Source : Manufacturing Processes for Engineering Materials,5rdrd Edition., S. Kalpakjian and S. Schmid, 2008 , Edition., S. Kalpakjian and S. Schmid, 2008 , Additional references in the last slide
Continuous-Casting
(a) The continuous-casting process for steel. Note that the platform is about 20 m (65 ft) above ground level. Source: American Foundrymen's Society.
(b) (b) Continuous strip casting of nonferrous metal strip. Source: Courtesy of Hazelett Strip-Casting Corp.
Source : Manufacturing Processes for Engineering Materials,5Source : Manufacturing Processes for Engineering Materials,5rdrd Edition., S. Kalpakjian and S. Schmid, 2008 , Edition., S. Kalpakjian and S. Schmid, 2008 , Additional references in the last slide
Description: Permanent Mold Casting Capabilities
Horacio Elizondo Author
April 2003Date
Alting,Leo. “Manufacturing Processes Reference Guide.” 1994Reference
Shape Material Conserve Material Consolidation Function – Sub function
Source : Manufacturing Processes for Engineering Materials,5Source : Manufacturing Processes for Engineering Materials,5rdrd Edition., S. Kalpakjian and S. Schmid, 2008 , Edition., S. Kalpakjian and S. Schmid, 2008 , Additional references in the last slide
Pressure & Hot-Chamber Die Casting
FIGURE 5.23 The pressure casting process, utilizing graphite molds for the production of steel railroad wheels. Source: Griffin Wheel Division of
Amsted Industries Incorporated .
FIGURE 5.24 Schematic illustration of the hot-chamber die-casting process .
Source : Manufacturing Processes for Engineering Materials,5Source : Manufacturing Processes for Engineering Materials,5rdrd Edition., S. Kalpakjian and S. Schmid, 2008 , Edition., S. Kalpakjian and S. Schmid, 2008 , Additional references in the last slide
Description: Hot Chamber Die Casting Capabilities
Horacio Elizondo Author
April 2003Date
Alting,Leo. “Manufacturing Processes Reference Guide.” 1994Reference
Shape Material Conserve Material Consolidation Function – Sub function
Source : Manufacturing Processes for Engineering Materials,5Source : Manufacturing Processes for Engineering Materials,5rdrd Edition., S. Kalpakjian and S. Schmid, 2008 , Edition., S. Kalpakjian and S. Schmid, 2008 , Additional references in the last slide
Cold-Chamber Die Casting
FIGURE 5.25 Schematic illustration of the cold-chamber die-casting process. These machines are large compared to the size of the casting, because high forces are required to keep the two halves of the die closed
under pressure .Source : Manufacturing Processes for Engineering Materials,5Source : Manufacturing Processes for Engineering Materials,5rdrd Edition., S. Kalpakjian and S. Schmid, 2008 , Edition., S. Kalpakjian and S. Schmid, 2008 , Additional references in the last slide
Source : Manufacturing Processes for Engineering Materials,5Source : Manufacturing Processes for Engineering Materials,5rdrd Edition., S. Kalpakjian and S. Schmid, 2008 , Edition., S. Kalpakjian and S. Schmid, 2008 , Additional references in the last slide
Die Casting
Source : Manufacturing Processes for Engineering Materials,5Source : Manufacturing Processes for Engineering Materials,5rdrd Edition., S. Kalpakjian and S. Schmid, 2008 , Edition., S. Kalpakjian and S. Schmid, 2008 , Additional references in the last slide
Centrifugal Casting
FIGURE 5.26 Schematic illustration of the centrifugal casting process. Pipes, cylinder liners, and similarly shaped hollow parts can be cast by this process .
Source : Manufacturing Processes for Engineering Materials,5Source : Manufacturing Processes for Engineering Materials,5rdrd Edition., S. Kalpakjian and S. Schmid, 2008 , Edition., S. Kalpakjian and S. Schmid, 2008 , Additional references in the last slide
Source : Manufacturing Processes for Engineering Materials,5Source : Manufacturing Processes for Engineering Materials,5rdrd Edition., S. Kalpakjian and S. Schmid, 2008 , Edition., S. Kalpakjian and S. Schmid, 2008 , Additional references in the last slide
Source : Manufacturing Processes for Engineering Materials,5Source : Manufacturing Processes for Engineering Materials,5rdrd Edition., S. Kalpakjian and S. Schmid, 2008 , Edition., S. Kalpakjian and S. Schmid, 2008 , Additional references in the last slide
Semicentrifugal Casting
FIGURE 5.27 (a) Schematic illustration of the semicentrifugal casting process. Wheels with spokes can be cast by this process. (b) Schematic illustration of casting by centrifuging. The molds are placed at the
periphery of the machine, and the molten metal is forced into the molds by centrifugal forces .
Source : Manufacturing Processes for Engineering Materials,5Source : Manufacturing Processes for Engineering Materials,5rdrd Edition., S. Kalpakjian and S. Schmid, 2008 , Edition., S. Kalpakjian and S. Schmid, 2008 , Additional references in the last slide
Source : Manufacturing Processes for Engineering Materials,5Source : Manufacturing Processes for Engineering Materials,5rdrd Edition., S. Kalpakjian and S. Schmid, 2008 , Edition., S. Kalpakjian and S. Schmid, 2008 , Additional references in the last slide
Properties of Die-Casting Alloys
TABLE 5.6 Properties and typical applications of common die-casting alloys.
Source : Manufacturing Processes for Engineering Materials,5Source : Manufacturing Processes for Engineering Materials,5rdrd Edition., S. Kalpakjian and S. Schmid, 2008 , Edition., S. Kalpakjian and S. Schmid, 2008 , Additional references in the last slide
Rotor Microstructure
FIGURE 5.22 Microstructure of a rotor that has been investment cast (top) and conventionally cast (bottom). Source: Advanced Materials and Processes, October
1990, p. 25. ASM International .Source : Manufacturing Processes for Engineering Materials,5Source : Manufacturing Processes for Engineering Materials,5rdrd Edition., S. Kalpakjian and S. Schmid, 2008 , Edition., S. Kalpakjian and S. Schmid, 2008 , Additional references in the last slide
Fluid Flow and Heat Transfer
Bernoulli’s theorem Based on
- principle of conservation of energy - frictional losses in a fluid system
Conservation of energy requires that,
Constant 2
2
g
v
g
ph
h = elevationp = pressure at elevation
v = velocity of the liquidρ = density of the fluid
fg
v
g
ph
g
v
g
ph
2
2
222
2
211
1
Source : Manufacturing Processes for Engineering Materials,5Source : Manufacturing Processes for Engineering Materials,5rdrd Edition., S. Kalpakjian and S. Schmid, 2008 , Edition., S. Kalpakjian and S. Schmid, 2008 , Additional references in the last slide
Fluid Flow and Heat Transfer- Fluid flow
Mass continuity States that for an incompressible liquid the rate
of flow is constant.
Subscripts 1 and 2 pertain to two different locations in the system.
2211 vAvAQ Q = volumetric rate of flowA = cross-sectional area of the liquid streamv = velocity of the liquid
Source : Manufacturing Processes for Engineering Materials,5Source : Manufacturing Processes for Engineering Materials,5rdrd Edition., S. Kalpakjian and S. Schmid, 2008 , Edition., S. Kalpakjian and S. Schmid, 2008 , Additional references in the last slide
Fluid Flow and Heat Transfer- Fluid flow
Sprue profile Relationship between height and cross-sectional area
at any point in the sprue is given by
Velocity of the molten metal leaving the gate is
When liquid level reached height x, gate velocity is
1
2
2
1
h
h
A
A
ghcv 2
xhgcv 2Source : Manufacturing Processes for Engineering Materials,5Source : Manufacturing Processes for Engineering Materials,5rdrd Edition., S. Kalpakjian and S. Schmid, 2008 , Edition., S. Kalpakjian and S. Schmid, 2008 , Additional references in the last slide
Fluid Flow and Heat Transfer- Fluid flow
Flow characteristics Reynold’s Number Ratio of momentum (inertia) to viscosity Fluid flow in gating systems is turbulence, as opposed to
laminar flow. (Which flow is preferred?) Reynolds number, Re, is used to characterize this aspect
of fluid flow.
Higher the Re, greater the tendency for turbulent flow.
vD
Re
v = velocity of the liquidD = diameter of the channelρ = density n = viscosity of the liquid.
Source : Manufacturing Processes for Engineering Materials,5Source : Manufacturing Processes for Engineering Materials,5rdrd Edition., S. Kalpakjian and S. Schmid, 2008 , Edition., S. Kalpakjian and S. Schmid, 2008 , Additional references in the last slide
Critical Reynold’s Number
• Re ~ 2,000– Laminar to turbulent transition
– Eddies begin to form
• Re > 20,000– very turbulent
Source : Manufacturing Processes for Engineering Materials,5Source : Manufacturing Processes for Engineering Materials,5rdrd Edition., S. Kalpakjian and S. Schmid, 2008 , Edition., S. Kalpakjian and S. Schmid, 2008 , Additional references in the last slide
How fast would a stream of honey 1 in. in diameter need to be turbulent?
Density (ρ) = 1.43 g/cm3 (at 20oC)Viscosity () = 189 poise (at 20.6oC)
vD
Re
9.18
1430254.0Re
v
turbulent flow transition Re ~ 2,000
Re = 2,000 = 1,430 * V * 0.0254/18.9
V = 1,040 m/s )This ignores shear thinning(.
Example 1
Source : Manufacturing Processes for Engineering Materials,5Source : Manufacturing Processes for Engineering Materials,5rdrd Edition., S. Kalpakjian and S. Schmid, 2008 , Edition., S. Kalpakjian and S. Schmid, 2008 , Additional references in the last slide
The desired volume flow rate of the molten metal into a mold is 0.01 m3/min .
The top of the sprue has a diameter of 20 mm and its length is 200 mm.
What diameter should be specified at the bottom of the sprue in order to prevent aspiration?
What is the resultant velocity and Reynolds number at the bottom of the sprue if the metal being cast is aluminium and has a viscosity of 0.004 N-s/m2
Solution
Since d1 = 0.02 m
The metal volume flow rate is Q= 0.01 m3/min = 1.667×10-4 m3/s 1Top, 2 bottom
Therefore
Example 5.2 Design and analysis of a sprue for casting
m/s 531.01014.3
10667.14
4
11
A
Qv
24221 m 1014.3002.0
44
dA
Source : Manufacturing Processes for Engineering Materials,5Source : Manufacturing Processes for Engineering Materials,5rdrd Edition., S. Kalpakjian and S. Schmid, 2008 , Edition., S. Kalpakjian and S. Schmid, 2008 , Additional references in the last slide
m/s 45.12 v
Assuming no frictional losses, and recognizing that the pressure at the top and bottom of the sprue is atmospheric
Thus ,
fg
v
g
ph
g
v
g
ph
2
2
222
2
211
1 0
81.92
81.92
531.02.0
22
2
v
g
p
g
p atmatm
242 m 1015.1 A22vAQ 45.1101.667 2
4 A
22 4
dA
24
41015.1 d
mmd 12
Source : Manufacturing Processes for Engineering Materials,5Source : Manufacturing Processes for Engineering Materials,5rdrd Edition., S. Kalpakjian and S. Schmid, 2008 , Edition., S. Kalpakjian and S. Schmid, 2008 , Additional references in the last slide
745,11
004.0
2700012.045.1Re
vD
In calculating the Reynolds number
3/2700 mkg
As stated above, this magnitude is typical for casting molds, representing a mixture of laminar and turbulent flow
An Re value of up to 2000 represents laminar flow An Re Between 2000 and 20,000 it is a mixture of laminar and turbulent flow and is generally regarded as harmless in gating systems for casting Re values in excess of 20,000 represent severe turbulence.
v = velocity of the liquidD = diameter of the channelρ = density n = viscosity of the liquid.
Source : Manufacturing Processes for Engineering Materials,5Source : Manufacturing Processes for Engineering Materials,5rdrd Edition., S. Kalpakjian and S. Schmid, 2008 , Edition., S. Kalpakjian and S. Schmid, 2008 , Additional references in the last slide
Physical Properties of Materials
TABLE 3.3 Physical Properties of Various Materials at Room Temperature.
Source : Manufacturing Processes for Engineering Materials,5Source : Manufacturing Processes for Engineering Materials,5rdrd Edition., S. Kalpakjian and S. Schmid, 2008 , Edition., S. Kalpakjian and S. Schmid, 2008 , Additional references in the last slide
Heat transfer
Heat flow depends on casting material and the mold and process parameters.
Temperature distribution in the mold-liquid metal interface is shown below.
Source : Manufacturing Processes for Engineering Materials,5Source : Manufacturing Processes for Engineering Materials,5rdrd Edition., S. Kalpakjian and S. Schmid, 2008 , Edition., S. Kalpakjian and S. Schmid, 2008 , Additional references in the last slide
22
,int_
1
4
casting
casting
moldmoldmoldinitilmoldpomelting
CastingCasting
A
v
ckTTt
2
,int_
casting
casting
initilmoldpomelting
CastingCasting
A
v
TTht
Solidification time (t) for an insulating mold (α mold << α casting; k mold << k casting)
Solidification time (t) for a conducting mold (Biot # =hl/k < 0.17)
ΔH = latent heat for the process = Hf + ΣCiΔTHf = latent heat of solidification (fusion)V = volumeA = areah = heat transfer coefficientC = specific heatρ = density
Source : Manufacturing Processes for Engineering Materials,5Source : Manufacturing Processes for Engineering Materials,5rdrd Edition., S. Kalpakjian and S. Schmid, 2008 , Edition., S. Kalpakjian and S. Schmid, 2008 , Additional references in the last slide
Chvorinov’s rule for solidification time for a conducting mold
t = K (V/A)
Chvorinov’s rule for solidification time for an insulating mold
t = cooling timeK = a constantV = volumeA = area
2
A
VKt
Cooling time (t) for a solid object for a small Biot number (Biot # =hl/k < 0.17)
finalcastingpomelting
initilcastingmoldcastingcasting
casting
casting
TT
TT
h
C
A
vt
,int_
,ln
Source : Manufacturing Processes for Engineering Materials,5Source : Manufacturing Processes for Engineering Materials,5rdrd Edition., S. Kalpakjian and S. Schmid, 2008 , Edition., S. Kalpakjian and S. Schmid, 2008 , Additional references in the last slide
moldtotaltotal
gate
moldf hhh
gA
At
2
2
total
bapouring
sprueofbottom
sprueoftop
sprueoftop
spreueofbottom
h
h
v
v
A
A sin,
..
..
..
..
Filling time for a bottom-gated mold
For no aspiration
Mold filling time estimate
gategatevA
volumeMoldt
.
Source : Manufacturing Processes for Engineering Materials,5Source : Manufacturing Processes for Engineering Materials,5rdrd Edition., S. Kalpakjian and S. Schmid, 2008 , Edition., S. Kalpakjian and S. Schmid, 2008 , Additional references in the last slide
Material properties:Data for solid materials at room temperature
MaterialSpecific heat (C)(kJ/kg-oC)
Density (ρ)(kg/m3)
Thermal conductivity(k) (W/m-oC)
Sand1.1615000.60
Aluminum0.902700202
Nickel0.44891092
Magnesium1.071700156
Copper0.398970385
Gray cast iron0.441712542.7
Source : Manufacturing Processes for Engineering Materials,5Source : Manufacturing Processes for Engineering Materials,5rdrd Edition., S. Kalpakjian and S. Schmid, 2008 , Edition., S. Kalpakjian and S. Schmid, 2008 , Additional references in the last slide
MaterialMelting point(oC)
Latent heat ofsolidification (fusion)
)Hf) (kJ/kg(
Specific heat (C))kJ/kg-oC(
Viscosity)(
)mPa-s(
Aluminum6603961.051.3
Nickel14532970.73---
Magnesium6503841.381.04
Copper10832200.522.1
Gray cast iron
12512110.345.25
Data for liquid materials
Source : Manufacturing Processes for Engineering Materials,5Source : Manufacturing Processes for Engineering Materials,5rdrd Edition., S. Kalpakjian and S. Schmid, 2008 , Edition., S. Kalpakjian and S. Schmid, 2008 , Additional references in the last slide
Solidification time
Solidification time is a function of the volume of a casting and surface area (Chvorinov’s rule).
Effects of mold geometry and elapsed time on skin thickness and its shape are show.
n
C
Area Surface
Volumetion timeSolidifica C = constant
n = 2
Source : Manufacturing Processes for Engineering Materials,5Source : Manufacturing Processes for Engineering Materials,5rdrd Edition., S. Kalpakjian and S. Schmid, 2008 , Edition., S. Kalpakjian and S. Schmid, 2008 , Additional references in the last slide
Three pieces being cast have the same volume but different shapes. One is a sphere, one a cube, and the other a cylinder with a height equal to its diameter. Which piece will solidify the fastest and which one the slowest? Use n = 2.
SolutionThe volume is unity
Respective surface areas are
Respective solidification times t are
Example 5.3Solidification times for various solid shapes
54.522 :Cylinder
66 : Cube
84.44
34 :Sphere
2
2
3/2
rhrA
aA
A
2area Surface
1tion timeSolidifica
CtCCt cylindersphere 033.0 028.0 043.0 cubet
Source : Manufacturing Processes for Engineering Materials,5Source : Manufacturing Processes for Engineering Materials,5rdrd Edition., S. Kalpakjian and S. Schmid, 2008 , Edition., S. Kalpakjian and S. Schmid, 2008 , Additional references in the last slide
Shrinkage
Shrinkage in casting causes dimensional changes. Cracking is a result of:
1. Contraction of the molten metal
2. Contraction of the metal during phase change
3. Contraction of the solidified metal
For L->S, always think of
Solidification Shrinkage!!
Source : Manufacturing Processes for Engineering Materials,5Source : Manufacturing Processes for Engineering Materials,5rdrd Edition., S. Kalpakjian and S. Schmid, 2008 , Edition., S. Kalpakjian and S. Schmid, 2008 , Additional references in the last slide
Source : Manufacturing Processes for Engineering Materials,5Source : Manufacturing Processes for Engineering Materials,5rdrd Edition., S. Kalpakjian and S. Schmid, 2008 , Edition., S. Kalpakjian and S. Schmid, 2008 , Additional references in the last slide
Melting Practice and Furnaces
Melting has a direct bearing on the quality of castings. Fluxes are inorganic compounds that refine the molten
metal by removing dissolved gases and various impurities.
The metal charge may be composed of commercially pure primary metals, which can include remelted or recycled scrap.
Source : Manufacturing Processes for Engineering Materials,5Source : Manufacturing Processes for Engineering Materials,5rdrd Edition., S. Kalpakjian and S. Schmid, 2008 , Edition., S. Kalpakjian and S. Schmid, 2008 , Additional references in the last slide
Casting Alloys
Source : Manufacturing Processes for Engineering Materials,5rd Edition., S. Kalpakjian and S. Schmid, 2008 , Additional references in the last slideSource : Manufacturing Processes for Engineering Materials,5rd Edition., S. Kalpakjian and S. Schmid, 2008 , Additional references in the last slideP.P.P File Prepared by the author and publisher and other sourcesP.P.P File Prepared by the author and publisher and other sources
Bibliography (References). Manufacturing Processes for Engineering Materials,5rd Edition., S. Kalpakjian and S. Schmid, Prentice
Hill 2008 Materials and Processes in Manufacturing, 10th Edition, E. Paul DeGarmo, J. T. Black, Ronald A. Kohser
,2007.Manufacturing Engineering & Technology , Serope Kalpakjian , 6th Edition, Prentice Hall,2009.TECNOLOGI CO DE MONTERREY Mechanical Manufacturing, Professor Arturo Molina , October 2004.E. Paul DeGarmo et al, “Materials And Processes in Manufacturing”, Wiley Publishing Company 2003.
John E. Schey, “Introduction To Manufacturing Processes” McGraw-Hill Book Company,1988.Courtney, T. H., “ Mechanical Behavior of Materials”, N. Y., McGraw-Hill, 1990.E., George E. and George F., “ The Testing of Engineering Materials”, McGrraw-Hill Book Company.
1982.“Hardness Tests”, Metals Park, Ohio: ASM International, 1987.Harmer E., George E. and George F., “ The Testing of Engineering Materials”, McGrraw-Hill Book
Company. 1982.Halmshaw R. “ Non-Destructive Testing”, Edward Arnold, 1991.Courtney, T. H., “ Mechanical Behavior of Materials”, N. Y., McGraw-Hill, 1990.Jonathan S. Colton , Manufacturing Processes and Engineering, Georgia Institute of Technology, 2009.Pohlandt K., “ Material Testing for Metal forming Industry”, N.Y Springer 1989.Lawrence E. Doyle, “Manufacturing Process And Materials For Engineers”, Prentice-Hall, Third
Edition.T.T. EL-Midany & M.A. Mansour , Manufacturing Technology, King Abdulaziz University.S.F. Kvav et al., Machine Tool Operations, McGraw-Hill Book Company.Geoffrey Boothroyd, Fundamentals of Metal Machining and Machine Tools, McGraw-Hill Book
Company.Cold and Hot Forging Fundamentals and Applications, Taylan Altan ,al, ASM,2007.Fundamentals of Metal Forming ,Robert H. Wagoner,Jean-Loup,Wiley,1997.Metal Forming ,Willam F. Hosford Robert M. ,second Edition, PTR, 1993.