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1、光学级铝基复合材料热变形行为研究在欧美等发达国家,铝基复合材料的工业化生产已经开始,并且被列为21世纪新材料应用开发的重要方向。然而,由于在铝基体中加入了人量的硬质相颗粒,铝基复合材料的热加T性能与基体相比要下降很多,这在一定程度上阻碍了铝基复合材料的广泛应用;此外,由于增强体的加入使复合材料的组织变化与控制比传统材料更为复杂。因此,如何选择适当的热加工工艺,提高铝基复合材料的加工性能从而改善产品的显微组织成为日前所面临的关键课题。木文通过建立流变方程对铝基复合材料的热变形进行表征,得到的主要结论如下:Si
2、Cp/2024铝基复合材料高温热压缩变形时存在稳态流变特征,流变应力随着温度的升高而降低,随着应变速率的增人而提高。SiCp/2024铝基复合材料的高温变形受热激活控制,稳态流变应力可以表示为只包含Z参数的方程。不同颗粒含量的铝基复合材料在相同条件下会随着颗粒含量的增多而使其流变应力变人,且其流变应力都会随着温度的升高而减小。材料的表观激活能随颗粒含量增加而增大。关键词:铝基复合材料,流变应力,热激活,动态材料模型Studyonthedeformationbehaviorofopticalgradealum
3、inummatrixcompositeheatABSTRACTIndustrializedproductionofaluminummatrixcomposites(AMCs)hasbegunintheUnitedStates,Europeandotherdevelopedcountries,andthematerialwasclassifiedasanimportantdirectionofnewapplicationmaterialsfor21thcentury.However,duetotheexist
4、enceofhardparticlesinAMCs,hot-workingabilityofthematerialwasmuchworsethantheabilityofaluminumalloy,which,toacertainextent,blocksthewideapplicationofthematerial.Moreover,theexistenceoftheparticleswillalsomakeitmoredifficultytocontrolthemicrostructurechanges
5、ofAMCsduringhotdeformation.Therefore,howtochoosetheappropriatehotdeformationtechnologytoimprovethehotworkingabilityofAMCs,andfinallyimprovethemicrostructureoftheproductionbecomesacriticalissue.Thispaperwascharacterizedthroughtheestablishmentofrheologicaleq
6、uationofthealuminummatrixcompositethermaldeformation,themainconclusionsareasfollows:Steady-stateflowcharacteristicswereobservedduringhotdeformationofSiCp/7A04composites,andtheflowstressesincreasewiththeincreasingofstrainrateandthedecreasingoftemperature.Th
7、ehotdeformationsofthecompositesarecontrolledbythermalactivation,andtheflowstressesundertheexperimentalrangecanbeexpressedasafunctionofparameterZ・Aluminummatrixcompositeswithdifferentparticlecontentwillincreasewiththeparticlecontentandtheflowstressbecomesla
8、rgerunderthesameconditions,andtheflowstressdecreaseswiththeincreaseoftemperature.Thematerialoftheapparentactivationenergyincreasesw让hincreasingparticlecontentKEYWORDS:aluminummatrixcomposites,flowstress,therm