Microstructure and mechanical properties of TC21 titanium alloy by near-isothermal forging  

近等温锻造后TC21钛合金的显微组织及力学性能(英文)

作　　者：石志峰[1] 郭鸿镇[1] 刘瑞[1] 王晓晨[1,2] 姚泽坤[1] 

机构地区：[1]西北工业大学材料学院,西安710072 [2]西北工业大学航空学院,西安710072

出　　处：《Transactions of Nonferrous Metals Society of China》2015年第1期72-79,共8页中国有色金属学报（英文版）

基　　金：Projects(51205319,51101119)supported by the National Natural Science Foundation of China

摘　　要：Microstructure and tensile properties of TC21 titanium alloy after near-isothermal forging with different parameters plus solution treatment and aging were investigated. It is found that the residual β matrix, which was strengthened by fine secondary α platelets forming during aging, exists in all the samples; while primary equiaxed α phase, bent lamellar α phase and α plates are simultaneously or individually present in one sample. The strength of alloy increases proportionally with increasing the content of residual β matrix, which is the result of increasing α/β interphase boundary. The plasticity of alloy has a downward trend as the content of residual β matrix increases. This attributes to the increase of fine secondary α platelets, which are cut by dislocations during the deformation. Additionally, coarse α plates with long axis parallel to the maximum resolved shear stress（MRSS） also reduce the plasticity of TC21 alloy.研究经不同参数近等温锻造并固溶时效热处理后TC21钛合金的显微组织及拉伸性能。结果表明,所有试样中都存在细小片状α相强化的残留β基体,而初生等轴α相、弯曲片状α相及片状α相可能同时或单独出现在试样中。残留β基体含量的增多会增加合金中α/β相界面,从而引起合金强度增加。随着残留β基体含量的增加,细小片状α相增多,变形过程中被位错切过,导致合金的塑性有下降趋势。另外,当长轴方向与最大剪切应力平行时,粗大的片状α相也会降低合金的塑性。

关 键 词：TC21 titanium alloy near-isothermal forging MICROSTRUCTURE α phase morphology residual β matrix tensile properties 

分 类 号：TG319[金属学及工艺—金属压力加工] TG146.23[一般工业技术—材料科学与工程]