近共晶Al-Si合金微觀組織與力學(xué)性能的研究.pdf

1、東南大學(xué)碩士學(xué)位論文近共晶AlSi合金微觀組織與力學(xué)性能的研究姓名：孫瑜申請學(xué)位級別：碩士專業(yè)：材料加工工程指導(dǎo)教師：孫國雄2001.3.1■JAbstractTherecentdevelopmentandresearchofA1Sicastingalloys，theStrengtheningmechanismandmethods，andtheeffectofthemainparametersonmechanicalproperties

2、ofAlSialloyswerereviewedStrengtheningeffectoftheheattreatmentandtherefinementofmicrostructureandthemechanicalpropertiesofneareutecticAI—SialloyswithexcellentcastabilityhavebeeninvestigatedFirst，theeffectofheattreatmentpr

3、ocessonmechanicalpropertiesofAlalloys，andthecourseoftheevolutionofSiphaseduringsolutiontreatmentwerestudiedSecondlyAI—ZrmasteralloysisusedasagrainrefinementinAI—Sialloys，andtheinfluenceofZronthegrowthbehaviorofthedendrit

4、eⅨphase，themorphologyandsizeofSiparticlesandthemechanicalpropertiesofalloys，wereinvestigatedSincethereWasfewreferencesonthestrengtheningeffectofheattreatmentofneareutecticA1Sialloys，andmanytechnicalfactorsareinvolved，and

5、theinfluentialdegreeofindividualfactoronmechanicalpropertiesofalloysWasnotcleareither，SOorthogonalexperimentWasappliedtoinspecttheeffectofheattreatmentonmechanicalpropertiesoftheA1alloysTheresultshowsthattheorderofthefac

6、torsaccordingtotheintensityoftheeffectonultimatetensilestrengthissolutiontime，agingtime，Mgcontent，agingtemperature，onelongationis：Mgcontent，solutiontime，agingtime，agingtemperaturetheresultindicates，attheoptimumvalueofthe

7、factors，themechanicalpropertiesofAl—1235％Sialloysmodifiedby004％Srcouldreach：abi315MPa，6≥6％TheobservationandquantitativemetallographicmeasurementunderanopticalmicroscopeandScanningElectronMicroscope(SEM)，showthattheSipart

8、iclesundergonecking，fragmentation，spheroidizationandcoarseningduringsolutiontreatmentIntheinitialstageofsolutiontreatment(20～250min)，dissolutionandfragmentationofSiparticlesweredominant，withprolongingsolutiontime，Siparti

9、clesbecamerounderandstubbier；asthetimelongerthan250min，Siparticleswerefragmentizedutterly，andwillstarttospheroidizeInmiddlestage(400600min)，thedegreeofspheroidizationbecomehigherwiththeshapefactors(SF)couldreachO92Inthef

10、inalperiod(aRer800min)themorphologyofSiphaseisdeteriorationinsteadofsphereduetothefacetsformThemorphologyofSiphasecertainlyshowsasignificantinfluenceonthemechanicalpropertiesoftheAIalloys，andonthegenerationandpropagation