片状组织TA15钛合金局部流动失稳预测  

Prediction of flow localization instability of TA15 titanium alloy with lamellar microstructure

作　　者：董显娟[1,2] 鲁世强[3] 李鑫[2] 王克鲁[2] 欧阳德来[3] 

机构地区：[1]南昌航空大学'航空材料热加工技术'航空科技重点实验室,江西南昌330063 [2]南昌航空大学航空制造工程学院,江西南昌330063 [3]南昌航空大学材料科学与工程学院,江西南昌330063

出　　处：《材料热处理学报》2013年第10期193-199,共7页Transactions of Materials and Heat Treatment

基　　金：江西省自然科学基金(20122BAB216015);江西省教育厅青年科学基金项目(GJJ11160);'航空材料热加工技术'航空科技重点实验室开放基金(Zk201001004);南昌航空大学博士启动基金(EA201103316)

摘　　要：采用THERMECMASTOR—Z型热加工模拟实验机对网篮和魏氏两种片状组织TA15钛合金在仪＋B两相区温度750～950℃、应变速率0．001—10s^-1范围进行等温恒应变速率压缩实验，对压缩变形后试样进行了光学金相和透射电镜显微组织观察，并利用Jonas局部流动失稳参数预测了两种片状组织TA15钛合金的局部流动失稳行为。结果表明：两种片状组织TA15钛合金在α＋B两相区低温（750～850℃）和高应变速率（0．1～10s^-1）范围变形时均会出现局部流动失稳，且局部流动失稳主要集中在原始B晶粒边界附近。当局部流动失稳参数大于5时，魏氏组织TA15钛合金会出现局部流动失稳；当局部流动失稳参数大于7时，网篮组织TA15钛合金才会出现局部流动失稳。发现用Jonas局部流动失稳参数预测合金局部流动失稳的发生还存在一定局限性。Isothermal constant strain rate compression tests of TA15 titanium alloy with basketweave and Widmanstatten microstructure were carried out by a THERMECMASTOR-Z hot working simulation testing machine in the temperature range of 750 - 950 ℃ and strain rate range of 0. 001 -10 s-1 in alpha and beta phase field. The corresponding microstructure of the compressed specimens was observed by metallographic and transmission electron microscopes. By using of flow localization instability parameter propounded by Jonas, the flow localization instability of TAI5 titanium alloy with lamellar microstructure was predicted. The results indicate that flow localization instability of TA15 titanium alloy with basketweave and Widmanstatten microstructure both occurs in the low temperature （750 -850 ℃ ） and high strain rate （0.1 - 10 s^-1 ） regions and is observed mainly at the boundaries of prior beta grains. When the flow localization instability parameter is higher than 5, the flow localization instability of TA15 titanium alloy with Widmanstatten microstructure will take place. When it is higher than 7, the flow localization instability of basketweave microstructure will take place. The prediction of flow localization instability by Jonas flow localization instability parameter has to be further improved.

关 键 词：TA15钛合金 局部流动失稳 等轴化 失稳参数 原始β晶粒边界 

分 类 号：TG146.23[一般工业技术—材料科学与工程]