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Type Of Casting Process

1. Sand Casting

2. Plaster Mould Casting3. Investment Casting

4. Shell Molding

5. Die Casting

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Sand Casting

Sand casting is the simplest method of casting aluminum. Sand is madeinto a mould ! forming around a "ooden #pattern#. $he pattern isremoved% the sand mould assemled and molten metal pored in. $heprocess is chosen for small production runs% for comple& shapecastings re'uiring intricate cores or for ver! large castings.

( Advantages)o" e'uipment costs)argest si*e of castings possile ! an! casting methodsuited to comple& shapes and cores+er! lo" gas porosit! is possileIt is a versatile casting process

( Limitations)o" casting rate

3,5mm minimum "all thic-nessPoor linear dimensional tolerances e.g. 4mm m/ough surface 0nishCoarse grain si*e compared to die castingCasting "eights in the range of .1 g , 1% gppro&imate economical 'uantit! range 1 , 1 castings.

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Plaster Mould Casting

( Permeale plaster moulds give a smoothsurface 0nish 6125 rms7 "ith a 0nersurface detail than is otainale "ith shellmoulds. Castings as thin as .5 mm are

possile. Slo" solidi0cation rates reduceinternal stresses so that an! casting distortionis negligile.

( Machining and 0nishing operations ma! eeliminated ! the use of plaster moulds. Small

holes ma! e cast to si*e read! for tapping.Surface 0nish and dimensional accurac!e'uates to die casting 'ualities. )M25 allo!sare commonl! cast ! this process.

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Investment Casting

$his casting method involves producing a #"a&pattern# ! in9ecting "a& or plastic into apattern die. $he pattern is attached to gating

and runner s!stems and this asseml! isdipped in a hard setting refractor! slurr!%"hich is then cured. $he pattern is meltedout of the mould to leave an e&act cavit!. $hemould is heated to cure the refractor! and to

volatoli*e the remaining "a& patternmaterial. $he moulds are a-ed and moltenmetal is poured into the mould cavit!. :nsolidi0cation of the casting% the mouldmaterial is ro-en a"a! from the castings.

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Shell Moulding

shell mould consists of a sand shell% var!ing in thic-nesset"een 4,1 mm. $he sand particles are ondedtogether "ith phenolic resins giving a permeale mould.

$he production of shell moulds ma! e automated "hichlends itself to medium to high production runs. $he resin

coated sand is placed on a hot metal pattern; this is 0redin an oven to harden the shell. fter cooling% the shell isremoved from the pattern and is read! for use. Moltenmetal is then poured into the shell mould cavit! andallo"ed to cool. $he mould material is ro-en o< thecasting. =etter dimensioned tolerances are possile than"ith sand moulding% "hich reduces machining costs. >inesurface 0nishes e'ual to that of permanent moulds12613 rms7 ma! e otained. and consistentl!reproducile thin castings "ith 0ne detail ma! e made.

$he process is more costl! than sand% permanent mouldor die casting.

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)i'uid metal is introduced in metallic molds?

$he in9ection of metal could e@

1. Ander inBuence of high h!draulic pressure"ith the die loaded on machine PDC7.

2. Ander inBuence of lo" pneumatic pressure"ith the die loaded on machine )PDC7.

3. Ander inBuence of ravit! Poured !hand7 in a stationar! mold% called DC.4. Ander inBuence of ravit! Poured !

hopper7 in a tilted mold and suse'uentl!straightened% called EDurville ProcessF

Die Casting

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Why Pressure Die casting

($he decision to choose Pressure Diecasting asthe preferred production method is generall!driven ! a re'uirement for high annual volume.s the annual demand increases% the lo"er piece

part price o

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Types Of Die Casting

( igh Pressure Die Casting PDC7

( )o" Pressure Die Casting )PDC7( ravit! Die Casting DC7

( +acuum high +acuum Die Casting

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!igh Pressure Die Casting

Pressure die casting is a repetitive process casting identical parts ! in9ectingluminum into metal moulds at pressures in the order of 1psi. Comple&machiner! and e&pensive tooling is re'uired for this process.

( dvantagesProduction rates ma! e in the order of 2 r

$hin "all thic-ness at 1 , 2.5mm$he est surface 0nish is produced ! this method

+er! 0ne grain structure is otained$he castings have high strength in the as,cast conditionood linear tolerances and repeatale properties are otained

( )imitationsSi*e of castings limited ! the machineSound% thic- sections are diGcult to castCore con0guration ma! e comple& to enale disasseml!Porosit! ma! ecome a concern

igh start up costs re'uire long production runs to reduce the overall costCastings cannot e heat treatedcasting "eight range .1 g , 25 gppro&imate economical 'uantit! range H 1% per annum.

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Lo" Pressure Die Casting

( $his is a repetitive process "here identical parts are cast ! in9ecting moltenmetal under lo" pressure into metal dies. $his process re'uires comple&machiner! and is similar to high pressure die casting.

( dvantages>air production rates up to 3 r

$hin "all thic-ness possile 2,3mm7=etter linear tolerances than gravit! casting

surface 0nish improved on gravit! casting% ut not up to pressure die castingstandardsigh ields possile as runners and risers not re'uired/educed 0nishing is re'uiredPore free castings are otainaleSand cores ma! still e used to allo" comple& castingsdie costs far lo"er than for pressure die castingCastings are heat treatale

( )imitationsSi*e of casting limited ! machine si*eProduction rates not up to pressure die casting>eeding thin sections through thic- sections is not recommendedcasting "eight range 5 g , 25 gppro&imate economical 'uantit! range H1

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#ravity Die Casting

Castings are produced ! poring molten metal into permanent metalmoulds. enerall! made from Cast Iron7.

$his process produces JChill CastingsE

( Advantages)o"er set up cost than Pressure Die castingigher casting rate than sand casting

)o" gas porosit! levels are possile>ine grain si*es ma! e otained

$he highest 'ualit! castings "ith regards to mechanical integrit! can eproduced ! this method)ess 0nishing is re'uired than for sand castings.

( LimitationsMinimum "all thic-ness 3,5mm)inear tolerance is appro&imatel! 3 mmmSurface 0nish etter than sand casting

$he comple&it! of possile casting shapes is limitedCasting "eight range .1 g , K gppro&imate economical 'uantit! range 5 , 25 $his ma! increase"here sand cores are used to produce shapes impossile "ith pressuredie casting.7

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Limited heat treata$leLimited "elda$le

The die can $e vented "iththe support of a vacuum

The %uality is increased"ith a moderate vacuum$et"een &'' and ('' m$ar

)acuum and high )acuum Die

casting The porosity setsthe limit tothe conventionalcasting

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Dosing Turbulence-free filling

Valve closing

IntensificationStart

Evacuation

High vacuum lower

than 50 mbar

Die concept (sealing)Die sprayingMelt treatmentMetal dosing

Additional measures

)acuum and high )acuum Diecasting

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Rp0,2 120-150 Mpa

Rm >180 Mpa

A5 >15%

Requirements to structural parts

)acuum and high )acuum Die

casting

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Cast parts are easily heat treatable an !el able

"i#h mechanical properties are reachable

"i#h consistency o$ this properties

&pensi'e but hi#h quality alloys can be cast economically

)acuum and high )acuum Die

castingAitional a'anta#es

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Space frame node

Climate control

$!pical vacuumdie cast parts

)acuum and high )acuum Diecasting

n entire ne" partspectrum for thedie caster

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Advantages of Die Casting

( Mass Production Process

( Consistent 'ualit! over mass production

( )east dependence on human s-ill igherengineering strength of materials

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*+TIt is an energy

intensive process

Continuous energy

input is aP,-,-%+ISIT-.

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And -nergy isgoing to $e ever

COSTLI-,.

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Aluminumis the most "idely used

metal for die casting.

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This is $ecause/

( It responds "ell to mold 0lling

( It is light in "eight

( Its thermal properties are e&cellent

( Its engineering strength iscomparale "ith steel.

( It is non,corrosive hence longerfunctional life.

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*+T

t higher temperature it has@

(Gnit! for o&!gen o&ide formation7( Gnit! for h!drogen causing gas porosit!7

( :&idation causes metal loss

( Porosit! causes re9ection

( >acilit! to control melting% holding of metaland casting parameters is essential?

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1. Magnesium

2. =rass3. Linc

Other Metals +sed In Die

Casting

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Initial cost ofe0uipment to melt andhold li0uid metal is

high.

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Investment is

called for in%uality Assurance

and -nergy SavingActivities.

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!igh Pressure Die

Casting.

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Casting parameters areest controlled ! this

process?

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It is also the mostproductive process of

casting "ith least energ!

consumption

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*ecause

( Casting process is carried out on machine.

( Modern machines are e'uipped "ith strictcasting parameter controls.

( Strength of castings% thus produced% is high.( /e9ection is least.

( n! deviation from set parameters is reported! audio signal and further production ishalted.

( Deviation report is availale onmicroprocessor hence 'uic- recti0cation.

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*+T( It does not accept any collapsi$le mold 1e2g2 Sand

Cores3

( -ach machine is designed for a speci4c range ofcasting si5e.

( Larger castings cannot $e made on a smaller

machine si5e2( Smaller castings can $e manufactured on larger

machine si5e using multi6cavity mold scheme2

( Multi6cavity mold scheme is 7usti4ed for large andconstant 0uantum o86ta9e2

( Such machines are costly.( Levels re0uired of plant cleanliness and tool :

machine maintenance are high2

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Some facts

( Modern Casting Purchasers1. nvisage e&cellent capailit! of vendor to produce

large series.

2. &pect in,time casting deliver! of goods.

3. Presume igh and Consistent Nualit! O Productivit!Standards.

4. ncourage onl! those vendors "ith IS: Nualit!Certi0cation.

( IS: Nualit! Certi0cation necessitatesstrict parameter control andDocumentation thereof.

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Mar9et Prospects

( PDC Castings are mainl!consumed all over the "orld !@

1. utomoile Industr!

2. lectrical O lectronic Industr!

3. Communication Industr! MoilePhones% )aptop =odies% etc.7

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-;port Mar9et for thedie cast products is note;ploited at all $y

Indian Die CastingIndustry.

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All this for the

fear andmagnitude of

Initial

Investment...

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Installing !PDC Capa$ility

re0uires( -;cellent mar9eting

strategy

( Strong 4nancial capa$ility

( Alert Purchase Policy( Accurate choice ofmachines

( Selective customer $ase

( Customers re0uiring largeseries 0uantities

( Customers "ith goodcredit rating

( +ninterrupted energysupply

( !igh tool designcapa$ility

( -0uipment to closely

control productionparameters

( !igh maintenancestandard

( Limited< yet s9illed