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Powder MetalPowder Metal

ProcessingProcessing

ManufacturingManufacturing

ProcessesProcesses

By:By:

Dr.Behzad HeidarshenasDr.Behzad Heidarshenas



OutlineOutline

IntroductionIntroduction

Powder ManufacturingPowder Manufacturing

Powder Metallurgy ProcessPowder Metallurgy Process

SinteringSintering

Other Powder Metal ProcessesOther Powder Metal Processes

Powder Metal ProductsPowder Metal Products

Powder Metallurgy DesignPowder Metallurgy Design



Powder MetallurgyPowder Metallurgy




MetalMetal

Powder Powder

Metal ProductMetal Product



Exa!les of PowderExa!les of Powder

Metal ProductsMetal Products"ears"ears

#as#as

#ran$s#ran$s

BearingsBearings

%oller &earing cages%oller &earing cages

HousingsHousings

'ight &ul& filaents'ight &ul& filaents

S!rin$ler echanissS!rin$ler echaniss



Powder Metal MaterialsPowder Metal Materials

EleentalEleental

( !ure etal) ost coonly ( !ure etal) ost coonly

iron) aluinu or co!!er iron) aluinu or co!!er

PrealloyedPrealloyed

(n alloy of the re*uired (n alloy of the re*uired

co!osition) ost coonlyco!osition) ost coonly

co!!er alloys) stainless steelco!!er alloys) stainless steel

or high+s!eed steelor high+s!eed steel




#on,ersion of olten etal to#on,ersion of olten etal to

!owder !owder

(toization (toization




Other ethods of !roducingOther ethods of !roducing

!owder:!owder:

+ #heical reduction of#heical reduction of!articulate co!ounds!articulate co!ounds

+ Electrolytic de!ositionElectrolytic de!osition

+ Pul,erization or grinding ofPul,erization or grinding of&rittle aterials&rittle aterials

+ -heral deco!osition-heral deco!osition

+ Preci!itation fro solutionsPreci!itation fro solutions+ #ondensation of etal ,a!ors#ondensation of etal ,a!ors



Particle Sha!eParticle Sha!e



Particle SizeParticle Size

-he !rocess of se!arating !articles-he !rocess of se!arating !articles

&y size is called classification&y size is called classification




Microgra!h of screened !owder !articles) showing

that !articles ay &e longer than the esh is wide




,oid

saller) ore nuerous ,oids

,oids filled &y saller !articles)

sall ,oids reain

Mixing !articles of different sizes allows decreased

!orosity and a higher !ac$ing ratio




ProcessProcess



Blending and MixingBlending and Mixing

BlendingBlending

#o&ining !owders of the sae aterial#o&ining !owders of the sae aterial

&ut !ossi&ly different !article sizes&ut !ossi&ly different !article sizes

MixingMixing

#o&ining !owders of different aterials#o&ining !owders of different aterials



#o!action#o!action

High !ressure is a!!lied to s*ueezeHigh !ressure is a!!lied to s*ueeze

the !owder into the desired sha!ethe !owder into the desired sha!e



Exa!le of a PowderExa!le of a Powder

PressPress



Other Powder MetalOther Powder Metal

ProcessesProcesses#old Isostatic Pressing#old Isostatic Pressing

Hot Isostatic PressingHot Isostatic Pressing

Inection MoldingInection Molding

Powder %ollingPowder %olling

Powder ExtrusionPowder Extrusion

Plasa S!rayingPlasa S!raying



Isostatic PressingIsostatic Pressing

/ses !ressurized fluid to co!ress the/ses !ressurized fluid to co!ress the!owder e*ually in all directions!owder e*ually in all directions

#old Isostatic Pressing#old Isostatic Pressing

#o!action !erfored at roo#o!action !erfored at roote!eraturete!erature

Hot Isostatic PressingHot Isostatic Pressing

Perfored at high te!eratures andPerfored at high te!eratures and

!ressures!ressures



Exa!le of an IsostaticExa!le of an Isostatic

PressPress



Inection MoldingInection Molding

-he !owder is ixed with a &inder-he !owder is ixed with a &inder

and olded) and the &inder isand olded) and the &inder is

reo,ed &efore sinteringreo,ed &efore sintering



Powder %ollingPowder %olling

Powder is co!ressed in a rolling illPowder is co!ressed in a rolling ill

to for a stri!to for a stri!



Powder ExtrusionPowder Extrusion

-he !owder can &e extruded within a-he !owder can &e extruded within a

container or after &eing fored intocontainer or after &eing fored into

&illets&illets




/ses a !lasa arc to !ro!el olten/ses a !lasa arc to !ro!el olten

dro!lets at a surface at a highdro!lets at a surface at a high

,elocity) foring a high+density,elocity) foring a high+densitystructurestructure



SinteringSintering

Heats the !owder &elow the eltingHeats the !owder &elow the elting

!oint to allow solid+state diffusion!oint to allow solid+state diffusion

and &ond the !articles together and &ond the !articles together



SinteringSintering

Diagra of !articles in sintering) showing the

!ossi&le o,eents of atos



SinteringSintering



Sintering ProductionSintering Production

'ines'ines



Exa!les of SinteringExa!les of Sintering

Production 'inesProduction 'ines



SinteringSintering

Strength of sintered structures as related to density)

showing that the strength is higher when the density

is higher 0less residual !orosity1



Powder Metal ProductsPowder Metal Products

2.2. Porous or !erea&lePorous or !erea&le!roducts!roducts

3.3. Products of co!lex sha!esProducts of co!lex sha!es4.4. Products ade of aterialsProducts ade of aterials

that are difficult to achine orthat are difficult to achine orha,e high elting !ointsha,e high elting !oints

5.5. Products which re*uire theProducts which re*uire theco&ined !ro!erties ofco&ined !ro!erties ofulti!le aterialsulti!le aterials

6.6. Products in which !owderProducts in which !owderetallurgy !roduces su!erioretallurgy !roduces su!erior!ro!erties!ro!erties




DesignDesign2.2. -he sha!e ust !erit reo,al-he sha!e ust !erit reo,al

fro the diefro the die

3.3. -he sha!e should not ha,e thin-he sha!e should not ha,e thinwalls or shar! cornerswalls or shar! corners

4.4. -he sha!e should !erit the-he sha!e should !erit the

construction of strong toolingconstruction of strong tooling

5.5. -he sha!e of the !art should &e-he sha!e of the !art should &e

within the thic$ness range forwithin the thic$ness range for

which the !owder can &e !ro!erlywhich the !owder can &e !ro!erly

co!actedco!acted

6.6. -he !art should ha,e as few-he !art should ha,e as few

changes in section thic$ness aschanges in section thic$ness as

!ossi&le!ossi&le




DesignDesign7.7. Parts can &e designed to ta$eParts can &e designed to ta$e

ad,antage of the ca!a&ilities ofad,antage of the ca!a&ilities of

the !owder etallurgy !rocessthe !owder etallurgy !rocess8.8. -he design should &e consistent-he design should &e consistent

with a,aila&le e*ui!entwith a,aila&le e*ui!ent

9.9. #onsideration should &e gi,en for#onsideration should &e gi,en for

!roduct tolerances!roduct tolerances.. Design should consider theDesign should consider the

diensional changes that occurdiensional changes that occur

after !ressing) such as shrin$ageafter !ressing) such as shrin$age

during sinteringduring sintering




DesignDesign




(d,antages (d,antages2.2. Eliination;reduction ofEliination;reduction of

achiningachining

3.3. High !roduction ratesHigh !roduction rates

4.4. #o!lex sha!es can &e#o!lex sha!es can &e

!roduced!roduced

5.5. <ide co!osition ,ariations<ide co!osition ,ariationsare !ossi&leare !ossi&le

6.6. <ide !ro!erty ,ariations are<ide !ro!erty ,ariations are

!ossi&le!ossi&le7.7. Scra! is eliinated orScra! is eliinated or

reducedreduced




Disad,antagesDisad,antages2.2. Inferior strength !ro!ertiesInferior strength !ro!erties

3.3. %elati,ely high die cost%elati,ely high die cost

4.4. High aterial costHigh aterial cost



SuarySuary

Powder etallurgy can createPowder etallurgy can create

!arts that would otherwise &e!arts that would otherwise &e

difficult to for) including thosedifficult to for) including thosewith co!lex sha!es orwith co!lex sha!es or

!orosity!orosity

Sintering &onds !articlesSintering &onds !articles

together &y allowing atos totogether &y allowing atos to

o,e) foring nec$s and graino,e) foring nec$s and grain

&oundaries &etween the&oundaries &etween the

!articles!articles

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