热处理对大规格等温模锻AZ80-Ag镁合金机匣显微组织和拉伸力学性能的影响  

Effects of heat treatment on microstructure and tensile mechanical properties of isothermal die forged AZ80−Ag casing with large size

作　　者：陈飞腾 蒋树农[1] 陈志永[1] 刘楚明[1,2] Fei-teng CHEN;Shu-nong JIANG;Zhi-yong CHEN;Chu-ming LIU(School of Materials Science and Engineering,Central South University,Changsha 410083,China;School of Materials Science and Engineering,Hunan University of Science and Technology,Xiangtan 411201,China)

机构地区：[1]中南大学材料科学与工程学院,长沙410083 [2]湖南科技大学材料科学与工程学院,湘潭411201

出　　处：《Transactions of Nonferrous Metals Society of China》2023年第8期2340-2350,共11页中国有色金属学报（英文版）

基　　金：the financial support from the National Natural Science Foundation of China(No.51874367)。

摘　　要：研究大规格等温模锻AZ80−Ag镁合金机匣在不同热处理条件下的组织演变和拉伸力学性能。采用扫描电镜和电子背散射衍射对合金的显微组织进行表征,并测试其在室温、120和150℃下的拉伸力学性能。结果表明,室温下强化作用更强的不连续析出相在T5样品中的面积分数高于T6样品的面积分数。因此,T5样品的析出强化作用更强,室温抗拉强度最高。但随着温度的升高,T5样品的抗拉强度迅速下降,在150℃时低于T6样品甚至锻造态样品的抗拉强度。这是由于不连续析出相的抗高温软化能力低于连续析出相的抗高温软化能力。The microstructure evolution and tensile mechanical properties of the isothermal die forged AZ80−Ag casing with large size under different heat treatment conditions were investigated.The microstructure was characterized by scanning electron microscope and electron backscatter diffraction techniques,and the tensile mechanical properties were tested at room temperature,120 and 150℃,respectively.The results show that the area fraction of discontinuous precipitates with stronger strengthening effect is higher in T5 sample than that in T6 sample,therefore T5 sample exhibits a more pronounced precipitation hardening and the highest tensile strength at room temperature.However,as the temperature increases,the tensile strength of T5 sample decreases rapidly and is lower than that of T6 sample or even the as-forged samples at 150℃.The reason is that discontinuous precipitates are less resistant to high temperature softening than continuous precipitates.

关 键 词：AZ80−Ag合金 热处理 高温拉伸性能 不连续析出相 析出强化 

分 类 号：TG156[金属学及工艺—热处理] TG146.22[金属学及工艺—金属学]