Morphology development of elongated α phases in hot working of large-scale titanium alloy plate  

大型TA15钛合金板坯热加工中α相形态演变(英文)

作　　者：樊晓光[1] 杨合[1] 高鹏飞[1] 严思梁 

机构地区：[1]西北工业大学材料学院,凝固技术国家重点实验室,西安710072

出　　处：《Transactions of Nonferrous Metals Society of China》2013年第12期3508-3516,共9页中国有色金属学报（英文版）

基　　金：Projects (50935007,51205317) supported by the National Natural Science Foundation of China;Project (2010CB731701) supported by the National Basic Research Program of China;Project (B08040) supported by Research Fund of the 111 Project

摘　　要：The role of subtransus hot working on microstructure morphology of TA15 titanium alloy plate with elongatedαphases was studied by quantitative metallography on different sections. The results show that the microstructure morphology is mainly affected by loading direction. When the sample is compressed along normal direction, microstructure on the section vertical to normal direction has equiaxed primaryαphase but microstructure on the section vertical to rolling direction has strip primaryαphase with long axis along tangential direction. When the sample is compressed along rolling direction, microstructure on the section vertical to normal direction has strip primaryαphase elongated along tangential direction but microstructure on the section vertical to rolling direction consists of strip and irregular broad-band primaryαphase. The strip primaryαphase aspect ratio is smaller at lower temperature due to the dynamic break-down ofαphase. The difference on primaryαphase aspect ratio between different sections decreases after compression along distinct directions in two loading passes, suggesting the improvement of equiaxity of primaryαphase.通过不同取向截面上的组织观测及定量金相分析,研究具有拉长α相的TA15钛合金板坯在两相区热加工中组织形态的演变机制。结果表明:变形后组织形态主要由加载方向决定;沿法线方向加载时,垂直于法线方向截面上的组织为等轴α相,而垂直于轧向截面上的组织沿切向拉长的条状α相;沿轧向加载时,垂直于法线方向截面上的组织为沿切向拉长的条状α相,而垂直于轧向截面上的组织为条状α相与宽带状α相混合的不均匀组织。变形温度较低时,由于α相的动态破碎,条状α相的轴比较小。变换加载方向进行两道次加载(先法向后轧向或先轧向后法向)时,两个截面上初生α相的轴比差较初始组织减小,等轴度有所提高。

关 键 词：microstructure morphology TA15 titanium alloy elongatedαphases subtransus hot working 

分 类 号：TG339[金属学及工艺—金属压力加工]