Static globularization and grain morphology evolution ofαandβphases during annealing of hot-rolled TC21 titanium alloy  

TC21钛合金热轧后退火过程中α和β相静态球化和晶粒形貌演变

作　　者：Ke WANG Ming-yu WU Zhao REN Yu ZHANG Ren-long XIN Qing LIU 王柯;吴明玉;任朝;张宇;辛仁龙;刘庆(重庆大学材料科学与工程学院轻合金材料国际合作联合实验室,重庆400044)

机构地区：[1]International Joint Laboratory for Light Alloys(MOE),College of Materials Science and Engineering,Chongqing University,Chongqing 400044,China

出　　处：《Transactions of Nonferrous Metals Society of China》2021年第9期2664-2676,共13页中国有色金属学报（英文版）

基　　金：The authors are grateful for the financial supports from the National Natural Science Foundation of China(No.51971046);the Fundamental Research Funds for the Central Universities,China(No.2020CDJGFCL005)。

摘　　要：A lamellar-structure TC21 titanium alloy was hot-rolled and subsequently annealed at 820,880 and 940℃ for 1 and 6 h,and the effects of annealing parameters on static globularization and morphology evolution of bothαandβphases were studied.The results show thatαglobularization process is sluggish due to the limited boundary splitting at 820℃.With increasing temperature to 880℃,the accelerated boundary splitting and termination migration promote theαglobularization.At 820 and 880℃,the static recovery(SRV)and recrystallization(SRX)induce the grain refinement of interlamellarβphase.However,the excessively high temperature of 940℃ results in the coarsening ofαgrains due to the assistance of Ostwald ripening,and produces coarseβgrains mainly due to the absence of SRX in interlamellarβphases.Conclusively,880℃ is an appropriate annealing temperature to produce a homogeneous microstructure in which globularizedαand refinedβgrains distribute homogeneously.对具有片层组织的TC21钛合金金进行热轧和退火试验(退火温度:820、880、940℃;退火时间:1、6 h),进而研究退火参数对α和β相静态球化和晶粒形貌的影响。结果表明:退火温度为820℃时,α球化不明显,这是由于片层α相中晶界分离机制受限所致。当退火温度升高到880℃时,晶界分离和末端迁移两种球化机制的发生促进片层α相的球化。在820和880℃退火时,静态回复和静态再结晶导致片层间β晶粒发生细化。然而,过高的退火温度(940℃)使得α晶粒在奥施特瓦尔德熟化作用下发生粗化,同时抑制片层间β相中静态再结晶的发生,产生粗大的β晶粒。因此,880℃是一个合适的退火温度;在该退火温度条件下可获得均匀的退火组织,其中球化的α晶粒和细化的β晶粒均匀分布。

关 键 词：TC21 titanium alloy αglobularization RECRYSTALLIZATION grain refinement 

分 类 号：TG146.23[一般工业技术—材料科学与工程]