压铸态7085铝合金的热变形行为与力学性能研究  

Study on Thermal Deformation Behavior and Mechanical Properties of Die-casting 7085 Aluminum Alloy

作　　者：赵晓东[1] 方越平 张奇柱 秦凤明 李亚杰[1] ZHAO Xiaodong;FANG Yueping;ZHANG Qizhu;QIN Fengming;LI Yajie(School of Materials Science and Engineering,Taiyuan University of Science and Technology,Taiyuan 030024,China)

机构地区：[1]太原科技大学材料科学与工程学院,山西太原030024

出　　处：《热加工工艺》2023年第15期22-25,共4页Hot Working Technology

基　　金：山西省自然科学基金项目(202103021224282,202103021223288);山西省重点研发计划项目(201903D121040)。

摘　　要：以压铸态7085铝合金为研究对象,采用三种工艺对其进行热压缩变形。采用光学显微镜(OM)对热压缩变形试样的微观组织进行观察和分析,采用电子万能试验机和扫描电子显微镜(SEM)对不同工艺下的试样进行力学性能测试和断裂行为分析。结果表明,该合金经不同道次变形后组织差别较大,单道次大应变变形后组织未发生明显的再结晶,为加工硬化状态,而多道次小应变累积的变形方式可激发少量的静态再结晶。单道次等温压缩后材料的屈服强度和抗拉强度较高,分别为402.6和480.7 MPa,断后伸长率从铸态的11.3%降低到9.3%。经固溶处理后材料的组织均匀性有明显改善,单道次等温压缩获得最佳综合力学性能,屈服强度降低到348.0 MPa,断后伸长率增加到20.9%,断口由变形态的沿晶断裂变为穿晶断裂。Taking the die-casting 7085 aluminum alloy as the research object,three kinds of processes were used for thermal compression deformation.Optical microscope(OM)was used to observe and analyze the microstructure of hot compression deformed samples,and electronic universal testing machine and scanning electron microscope(SEM)were used to test the mechanical properties and fracture behavior of samples under different processes.The results show that the microstructure of the alloy is quite different after different passes of deformation.After a single pass of large-strain deformation,the structure of the alloy has no obvious recrystallization,and it is in work-hardening state.The deformation mode of multi-pass small strain accumulation can stimulate a small amount of static recrystallization.The yield strength and tensile strength of the material after single-pass isothermal compression are higher,which are 402.6 and 480.7 MPa,respectively,and the elongation at break decreases from 11.3%of as-cast to 9.3%.Afer the solution treatment,the microstructure uniformity of the material is obviously improved,and the best comprehensive mechanical properties are obtained by single-pass isothermal compression,the yield strength is reduced to 348.0 MPa,and the elongation after fracture is increased to 20.9%.The fracture changes from intergranular fracture to transgranular fracture.

关 键 词：压铸态7085铝合金 热压缩 微观组织 力学性能 

分 类 号：TG306[金属学及工艺—金属压力加工] TG249.2