铸态TB6钛合金热变形过程中应力诱发马氏体相变  

Stress Induced Martensitic Transformation of As-cast TB6 Titanium Alloy During Hot Process

作　　者：欧阳德来[1] 崔霞[1] 鲁世强[1] 杜海明[2] Ouyang Delai;Cui Xia;Lu Shiqiang;Du Haiming(School of Materials Science and Engineering,Nanchang Hangkong University,Nanchang 330063,China;Jiangxi Normal University,Nanchang 330022,China)

机构地区：[1]南昌航空大学材料科学与工程学院,江西南昌330063 [2]江西师范大学,江西南昌330022

出　　处：《稀有金属材料与工程》2020年第11期3776-3781,共6页Rare Metal Materials and Engineering

基　　金：National Natural Science Foundation of China(51761029,51864035)。

摘　　要：对铸态TB6钛合金进行了恒应变速率热模拟压缩试验(变形温度为800~1150℃、应变速率为0.001~10 s^-1),研究了合金微观组织演变和应力诱导马氏体(SIM)相变。结果表明,该合金在热变形过程中出现了具有枝晶形态的正交结构SIM。SIM在β晶内和晶界形核。应变速率和变形温度控制合金成分均匀性和内应力,是SIM析出量的主要影响因素。不同应变速率的SIM析出量与变形温度范围有关。SIM析出量较高变形条件为:在800~900℃时应变速率为0.1 s^-1,900~1000℃时应变速率为0.01和1 s^-1,在1000℃以上时应变速率为1 s^-1。在变形温度925℃、应变速率1 s^-1时SIM析出量达最大化为50%。Hot compression tests of as-cast TB6 titanium alloy were performed at the temperature of 800~1150℃and the strain rate of 0.001~10 s^-1 to examine microstructure evolution associated with stress induced martensite(SIM).The results reveal the occurrence of the SIM with the dendritic morphology in the present alloy during hot compression process.The orthorhombic structure of SIM was confirmed for the alloy.It is found that the SIM nucleates both in theβgrain interior and at grain boundary.The alloy composition uniformity and internal stress are strongly dominated by strain rate and deformation temperature,which are responsible for the amounts of SIM.The content of SIM at different strain rate s is related to the temperature ranges.More SIM appear at the strain rate of 0.1 s^-1 for the temperature of 800~900℃,at 0.01 and 1 s^-1 for the temperature of 900~1000℃,at the strain rate of 1 s^-1 for the temperature of above 1000℃.50%martensite can be obtained at an optimal combination of the temperature of 925℃and the strain rate of 1 s^-1.

关 键 词：铸态TB6钛合金 马氏体 热变形 

分 类 号：TG146.23[一般工业技术—材料科学与工程]