新型Al-Cu-Li合金时效过程中组织和性能的变化研究.pdf

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1、第36卷第4期矿冶工程V〇1.36^42016年08月MININGANDMETALLURGICALENGINEERINGAugust2016新型Al-Cu-Li合金时效过程中组织和性能的变化研究$汪啸虎，刘志义，柏松，刘梦(中南大学材料科学与工程学院，湖南长沙410083)摘要：：通过拉伸试验和透射电镜（TEM)等分析测试手段，研究了一种新型A1-Cu-Li合金在固溶+预拉伸+人工时效过程中组织和性能的变化。结果表明，143尤下时效65h后合金的强度达到峰值，抗拉强度为559MPa,屈服强度为472MPa,延伸率为6.7%，塑性损失较

2、为严重;透射电镜(TEM)观察分析表明，合金中的主要析出相是T1相，S'相析出较少。2%预拉伸引人的适量密度位错为T1相提供了形核位置，既提高了T1相的形核率，又使T1相的分布均匀弥散。T1相的数量密度和尺寸随着时效的进行而增大。峰时效状态下，T1相长大较为明显，尺寸达到200nm，尺寸均匀性减弱。结合显微组织和拉伸性能比较分析，合金时效35h后可得到良好的组织和力学性能匹配。关键词：热处理；时效；A1-Cu-Li合金；预拉伸；微观组织；力学性能；T1相中图分类号：TG146.2文献标识码：Adoi:10.3969/j.issn.02

3、53-6099.2016.04.025文章编号：0253-6099(2016)04-0096-04InvestigationonMicrostructureandPropertyofNewlyDevelopedAl-Cu-LiAlloyduringAgingWANGXiao-hu，LIUZhi-yi，BAISong，LIUMeng(SchoolofMaterialsScienceandEngineering，CentralSouthUniversity，Changsha410083，Hunan，China)Abstract：Theev

4、olutionolmicrostructureandmechanicalpropertiesolanewlydevelopedA1-Cu-Lialloyduringtheprocessolsolutiontreatmentandpre-stretchingplusagingwasinvestigatedbytransmissionelectronmicroscopy(TEM)andtensiletesting.Theresultsshowedthatagingat143^lor65hresultedinthestrengtholAl-

5、Cu-Lialloyreachingthepeakvalue，thetensilestrength，yieldstrengthandelongationbeingat559MPa，472MPaand6.7%，respectively，withgreatplasticloss.TheTEMresultsshowedthatT1phasewasthemajorprecipitatewithlittleprecipitationolS'phase.Anappropriatedensityoldislocationsintroducedby2

6、%pre-stretchingprovidedanucleationpositionlorT1phase，notonlyincreasingthenucleationrateolT1phase，butalsomakingtheT1distributionhomogeneousanddispersive.ThenumberdensityandsizeolT1phaseincreasedwiththeincreaseolagingtime.Underthepeak-agedcondition，thegrowtholT1phasewasap

7、parentwiththesizereachingto200nm.However，thesizeunilormityolT1phasewasreduced.ThecomparativeanalysisolTEMandtensiletestingresultsindicatedthatagoodcombinationolmicrostructureandmechanicalpropertylortheAl-Cu-Lialloywasobtainedalteragingat143^lor35h.Keywords：heat-treatedp

8、rocess；aging；Al-Cu-Lialloy;pre-stretching；microstructure;mechanicalproperty;T1phase第三代Al-Li合金以其低密度、高强度、高韧性、基于这