資源描述：
《modeling the effects of mold topography on aluminum cast surfaces》由會(huì)員上傳分享，免費(fèi)在線閱讀，更多相關(guān)內(nèi)容在教育資源-天天文庫。
1、Solidi cationofAluminumAlloysEditedbyTMS(TheMinerals,Metals&MaterialsSociety),2004ModelingtheE ectsofMoldTopographyonAluminumCastSurfacesLijianTan1,NicholasZabaras11MaterialProcessDesignandControlLaboratory,188FrankH.T.RhodesHall,CornellUniversity,Ithaca,NY1485
2、3,USAKeywords:AluminumSolidi cation;Moldtopography;CastSurfacesAbstractTheair-gapnucleationtime,thestressevolutionandthesolidshellgrowthpatternareexaminedfordi erentmoldtopographiestoillustratethepotentialcontrolofaluminumcastsurfacemorphologiesduringtheearlyst
3、agesofsolidi cationusingproperdesignofmoldtopographies.Theinteractionbetweenheattransferanddeformationduringtheearlystagesofsolidi cationisconsideredinthiswork.Simulationresultsshowthatasinusoidalmoldsurfacewithasmallerwavelengthleadstoanearliernucleationofair-
4、gaps.Inaddition,theunevennessinthesolid-shellgrowthpatterndecreasesfasterforasmallerwavelength.Suchstudiescanbeusedtotunemoldsurfacesforcontrolofcastsurfacemorphologies.IntroductionStudyofthermalstressanddeformationdevelopmentduringaluminumcastingintheearlystag
5、esofsolidi cationcanbeanimportanttoolforunderstandingtheformationofcracks,liquationorotherdefectsintheingotsurface.Sincethemaindrivingforceofthermalstressdevelopmentinasolidifyingbodyisthetemperaturereductionprocess,controloftheheatextractionthroughthemold-shel
6、linterfaceduringtheearlystagesofsolidi cationisoneofthemostchallengingandimportantproblemsassociatedwithaluminumcasting.Incurrentpracticessurfacedefectsareremovedthroughexpensivesurfacemillingandscalpingprocesses.Understandingthee ectofmoldtopographyontheheatex
7、tractionprocessandtheresultingshellgrowthmayallowcertaincontrolofcastsurfacemorphologiesandthusleadtoareductionofunnecessarypost-castingoperationsneededtoremovesurfacedefects.Theanalysisofthedeformationofasolidifyingbodyissigni cantlydi erentfromthatofastandard
8、 xedbody.Thiswas rstdiscussedbyRichmond[1]andimplementedin[2,3]andintwo-dimensionalplanestressandaxisymmetricapplicationsbyZabarasetal.[4,5].Thesee ortsemphasizetheneedtoinc
