TA12A钛合金热处理过程中等轴和片层α相演变行为研究  

Evolution of Equiaxed and LamellarαPhase during Heat Treatment of TA12A Titanium Alloy

作　　者：陈飞 周瑜 王柯[2] Chen Fei;Zhou Yu;Wang Ke(Shaanxi Hongyuan Aviation Forging Company Ltd.,Xianyang 713801,China;School of Materials Science and Engineering,Chongqing University,Chongqing 400044,China)

机构地区：[1]陕西宏远航空锻造有限责任公司,陕西咸阳713801 [2]重庆大学材料科学与工程学院,重庆400044

出　　处：《钛工业进展》2021年第1期1-5,共5页Titanium Industry Progress

基　　金：国家自然科学基金项目(51971046)。

摘　　要：对近α型TA12A钛合金进行热处理实验,利用扫描电子显微镜(SEM)和电子背散射衍射(EBSD)技术对热处理后的微观组织进行观察,研究了两相区固溶温度和冷却速率对微观组织的影响。研究表明:TA12A钛合金在980和1000℃保温后冷却时,β相向α相转变,一方面可以使得等轴α相长大,另一方面也可析出片层α相。等轴α相长大过程中,新长大的区域与初始等轴α相存在成分差异,从而使新长大的区域在背散射电子成像模式下表现出α环状组织。空冷时,因冷却速率较快,使得片层α相快速形核并长大,从而抑制了等轴α晶粒的长大。但是,固溶温度对等轴α晶粒的长大和片层α相的析出行为影响较小。同时,冷却速率显著影响片层α相的形核位置,这与等轴α相的含量密切相关。Heat treatment experiments were conducted on the near-αtitanium alloy TA12A.The microstructure was observed using scanning electron microscopy(SEM)and electron backscattered diffraction(EBSD)method,and the effect of solution temperature in two phase region and cooling rate on the microstructure evolution was investigated.The results show that,during the cooling process after holding at 980 and 1000℃,the transformation fromβphase toαphase could make equiaxedαgrain grow up and lamellarαphase precipitate.During the growth of equiaxedαgrain,the composition of the new-growth region is different from that of the initial equiaxedαgrain,which makes the new-growth region show anαring structure under the SEM observation.The air cooling makes the lamellarαphase nucleate and grow rapidly,thus inhibiting the growth of equiaxedαgrains.However,the solution temperature has little effect on the growth of equiaxedαgrain and the precipitation of lamellarαphase.Furthermore,the cooling rate has a significant effect on the nucleation site of lamellarαphase,which is closely related to the content of equiaxedαgrain.

关 键 词：TA12A钛合金 热处理 等轴α晶粒 片层α相 

分 类 号：TG166.5[金属学及工艺—热处理] TG146.23[金属学及工艺—金属学]