24/10/201GM-KD5025grindingmachinebody（41T）castingpartVolume2Volume2CastingCasting1.Casting1.CastingCastingliquidalloyintothecastingcavitywhichadaptstotheshapeandsizeofthepart,tobecooledandsolidified,toobtaintheproductionmethodofblankorparts,iscalledcasting24/10/20224/10/203meltingofmetalCastingmouldofliquidmetalTobeacastingpartafterclearChapter1FoundamentalProcessofCastingⅠ.Castingliquidalloyintothecastingcavitywhichadaptstotheshapeandsizeofthepart,tobecooledandsolidified,toobtaintheproductionmethodofblankorparts,iscalledcasting.24/10/204Ⅱ.CharacteristicsofCasting１.Canbemadetocomplicatedform，especiallyfortheworkblankwithcomplicatedlumen；２.Thecastingweightandthealloycanbeusedareunrestricted；３.Hassmallallowanceofmachingandlowcost。Therefore，thecastingprocessiswidelyapplicated.But,(1)tensilestrengthandimpacttoughnessarenotasgoodasforgingandwelding.(2)complicatedprocess，higherrejectrate.24/10/205ⅠⅠ.concept.concept：：processofliquidalloyprocessofliquidalloyfillinginthecastingmold—Moldfillinginthecastingmold—MoldFilling.CapbilityofliquidalloyFilling.Capbilityofliquidalloyfullyfullyfillinginthemoldfillinginthemold，，togetcompletetogetcompleteform,clearedgesharpness--Liquidform,clearedgesharpness--LiquidAlloyAlloyFillingFillingAbility.Ability.spiralspecimenSection1Section1MoldFillingofLiquidAlloyMoldFillingofLiquidAlloyⅡ.LiquidAlloyfillingcapacityinfluencefactors：１.Mobilityofalloy（commonlymeasuredbyspiralspecimen）：Mobility，FillingCapacity，moreeasiertogetedgesharpness-thin-complicatedcastingpart.24/10/2061)MeasurementofAlloyMobility：byspiralspecimen.Underthesamepouringcondition，thelongerspiralspecimen，thebetterMobility。2)Influenceoffactors：mainlychemicalingredient.Thedistanceofliquidusandsolidus（Tl－Ts）iscalledMetacollid.２.Pouringcondition(Pouringtemperature,moldfillingpressure）：temperature，pressure--Moldfillingcapability.３.castingmouldfillingcondition（moldheatstoragecapacity，moldtemperatureandthegasesinmold）：heatstoragecapacity，moldtemperature，gasesexaustingcondition--MoldFillingCapability。Lowmoldfillingcapabilitycanresultsindefects：ColdShut、Shortrun(misrun).Fe-Calloymobility--carboncontentThebiggerMetacollidhas,theAlloymobilityisworse,andviceversa.Fig.24/10/207CastingsolidificationpatternSection2Section2CastingsolidificationandshrinkⅠ.Castingpartsolidificationsolidifylayerbylayer（充型能力好，便于补缩）１.凝固方式糊状凝固(易形成缩孔、难以获得结晶紧实的铸件）pastysolidfyingmiddlesolidfying中间凝固（介于上两者间）solidificationpattern(S-D)ingredientstemperatureS.L.SurfacecentreCastingpartLiquidussolidus24/10/208Rangeofalloycrystaltemperature２、S-DmaininfluencefactorsTEMPgradientalloypropertyheatstoragecapacitypouringTEMPⅡ.CastingAlloyShrink(Shrinkage)Ontheprocessofpouring、solidfying、coolingtilltoindoortemperature，thephenomenonthatthevolumeandsizereduce,iscalledshrink.1.Essenceofshrink：electronholereducingwithTEMP，atomicseparationshortened,thevolumeandsizereduced。liquidshrinkεl：Tp~Tl２.Clasificationsolidfyingshrinkεs：Tl~Tp,solidshrinkεs:Ts~IndoorTEMP。S-Dinfluencefactors24/10/209Ⅲ.shrinkagecavityandshrinkageporosityincastingpart１.Formingofshrinkagecavityandshrinkageporosity：Intheliquidalloycondensationprocess，iftheabbreviatedvolumecannotbecomplemented，thecavitiesandholeswillbegeneratedatthefinalsolidficationposit...
