Morphology transformation of primary strip α phase in hot working of two-phase titanium alloy  

两相钛合金热加工中初生带状α相形态演变（英文）

作　　者：Xiao-guang FAN He YANG Peng-fei GAO Rui ZUO Peng-hui LEI Zhe JI 樊晓光;杨合;高鹏飞;左瑞;雷鹏辉;吉喆(西北工业大学材料学院凝固技术国家重点实验室,西安710072)

机构地区：[1]State Key Laboratory of Solidification Processing, School of Materials Science and Engineering,Northwestern Polytechnical University, Xi’an 710072, China

出　　处：《Transactions of Nonferrous Metals Society of China》2017年第6期1294-1305,共12页中国有色金属学报（英文版）

基　　金：Projects(51205317,51575449) supported by the National Natural Science Foundation of China;Project(3102015AX004) supported by the Fundamental Research Funds for the Central Universities,China;Project(104-QP-2014) supported by the Research Fund of the State Key Laboratory of Solidification Processing,China

摘　　要：Microstructural development in hot working of TA15titanium alloy with primary stripαstructure was investigated withthe aim to globularizeαstrips.Results show that the mechanisms of morphology transformation are the same to the spheroidizationmechanisms of lamellar structure.Boundary splitting and termination migration are more important than coarsening due to the largesize of stripα.Theαstrips are stable in annealing due to the unfavorable geometrical orientation of intra-αboundaries,the largethickness of strip and the geometrical stability ofαparticles.Predeformation and low speed deformation accelerate globularization ofαstrips in the following ways:direct changing of particle shape,promotion of boundary splitting and termination migration byincreasing high angle grain boundaries and interfacial area,promotion of coarsening by forming dislocation structures.Largepredeformation combined with high temperature annealing is a feasible way to globularize stripα.为实现钛合金初生带状α相的球化,以具有这种组织的TA15钛合金为对象,研究其在热加工中的组织演变。结果表明:带状α相形态演变的机理与片层组织球化机理相同。由于带状α相尺寸较大,界面分离和末端物质迁移机制较粗化更为重要。带状α相在退火中较为稳定,主要原因是:内部晶界的几何取向不利于球化、带状组织的宽度较大和α粒子几何稳定性高。预变形和低速变形通过以下方式加速球化:直接改变α相的几何形状、通过增加大角度晶界以及相界的面积促进界面分离和末端物质迁移、通过形成位错结构促进粗化。采用大预变形结合高温退火是球化带状α相的有效途径。

关 键 词：titanium alloy primary α strips globularization morphology transformation hot working COARSENING 

分 类 号：TG146.23[一般工业技术—材料科学与工程]