中温热处理对Ti65合金淬火组织及室温拉伸性能的影响  

Effect of Medium Heat Treatment on Quenched Microstructure and Tensile Properties of Ti65 Alloy

作　　者：谭海兵 臧健 梁弼宁 刘建荣[1] 王清江[1] 赵子博[1] 李文渊 TAN Haibing;ZANG Jian;LIANG Bining;LIU Jianrong;WANG Qingjiang;ZHAO Zibo;LI Wenyuan(Shi-changxu Innovation Center for Advanced Materials,Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China;School of Materials Science and Engineering,University of Science and Technology of China,Shenyang 110016,China)

机构地区：[1]中国科学院金属研究所师昌绪先进材料创新中心,沈阳110016 [2]中国科学技术大学材料科学与工程学院,沈阳110016

出　　处：《材料研究学报》2023年第12期881-888,共8页Chinese Journal of Materials Research

基　　金：国家科技重大专项(J2019-VI-0012-0126)。

摘　　要：研究了中温热处理后Ti65合金中淬火马氏体相的分解及其对室温拉伸性能的影响。结果表明:在800℃/10 min热处理后Ti65合金中淬火马氏体相(α’相)内的β稳定元素向界面扩散,分解为α+β相;随着保温时间的延长,β相的形貌由不规则状转变为不同长宽比的棒状。热处理温度的提高,分解产物显著粗化。随着中温热处理温度升高或保温时间的延长,室温拉伸强度呈现快速降低、保持稳定和慢速降低三个阶段。强度快速降低的原因是,马氏体相分解使缺陷和界面密度降低,导致固溶和界面强化效果减弱;马氏体相完全分解后,α板条粗化导致的强度降低和α2相弥散度的提高使强度提高,其综合作用使强度保持相对稳定;中温热处理温度提高到α2相析出温度以上时,强度随着α板条厚度的增加缓慢降低。Heat treatments in the temperature range of 800~950℃for 10~60 min was applied to water-quenched Ti65 alloy,in order to investigate the martensite decomposition and its effect on tensile properties at room temperature.The results show that detectable martensite decomposition is already found at 800℃with a holding time of only 10 min.The martensite decomposition occurs through the diffusion ofβ-stabilizing elements from the interior ofα'plate to the interface to formβphase.The morphology of theβphase changes from irregular to regular rods of varied aspect ratio with prolonged holding time.Increasing temperature leads to apparent coarsening of the decomposition products.Both room-temperature tensile and yield strengths decrease after the heat treatments.Nearly constant strength was found for the heat treatments in the range from 800℃/40 min across 850℃20 min/40 min/60 min to 900℃/20 min.The decrease of strength is attributed mainly to the weakened solution strengthening induced by the decomposition of martensite phase.After the completion of the decomposition of the martensite phase,the strength remains almost constant due to the balance between the weakening induced by the coarsening ofαplate and the strengthening by the dispersedα2 particles.

关 键 词：金属材料 Ti65合金 中温热处理 马氏体相分解 拉伸性能 

分 类 号：TG132.32[一般工业技术—材料科学与工程]