摘要
对TA2纯钛剧烈塑性变形过程中的微观组织与力学性能的变化规律进行了研究。结果表明,原始的TA2纯钛由等轴的单一α相构成,平均晶粒尺寸约为48μm。ECAP变形和复合变形(ECAP+冷轧)可以有效细化晶粒,增加位错密度。在复合变形后,TA2纯钛的晶粒尺寸最为细小(约200 nm),位错密度更高,组织更加均匀。其屈服强度、抗拉强度和硬度均达到最大值,分别为732 MPa、856 MPa和238.6 HV,较原始TA2纯钛分别提高117.8%、77.59%和43.9%。此时其断裂伸长率最低,为10.8%。进一步的退火能够使复合变形的TA2纯钛发生回复和再结晶,有利于消除复合变形过程中的内应力,从而使得TA2纯钛的断裂伸长率提高至18.6%。总之,复合变形+退火的TA2纯钛具有优异的综合性能。
The changes of microstructure and mechanical properties of TA2 pure titanium during severe plastic deformation were studied. The results show that the microstructure of the original TA2 pure titanium consists of single and equiaxed α phase with an average grain size of about 48 μm. The ECAP deformation and composite deformation(ECAP+cold rolling) can effectively refine the grains and increase the dislocation density. After composite deformation, TA2 pure titanium has the smallest grain size(about 200 nm), higher dislocation density and more uniform microstructure. The yield strength, tensile strength and hardness reach the maximum value, which are 732 MPa, 856 MPa and 238.6 HV, respectively,which is 117.8%,77.59% and 43.9% higher than that of TA2 original pure titanium, respectively. However, the fracture elongation of TA2 pure titanium is the lowest of 10.8%. The further annealing can restore and recrystallize the TA2 pure titanium in the composite deformation, which is helpful to eliminate the internal stress during the composite deformation, thus increasing the fracture elongation of the TA2 pure titanium to 18.6%. All in all, the TA2 pure titanium with composite deformation + annealing has excellent comprehensive properties.
作者
张莉
潘爱琼
ZHANG Li;PAN Aiqiong(School of Mechanical Engineering,Zhengzhou University of Science&Technology,Zhengzhou 450064,China)
出处
《热加工工艺》
北大核心
2021年第15期26-29,共4页
Hot Working Technology
基金
河南省科技厅科技攻关项目(212102210348)。
关键词
TA2纯钛
复合变形
晶粒细化
位错
TA2 pure titanium
composite deformation
grain refinement
dislocation
作者简介
张莉(1985-),女,河南开封人,硕士,主要从事金属塑性成形理论及先进材料加工技术研究,电话:15286813790,E-mail:2115752270@qq.com.com;通讯作者:潘爱琼,讲师,研究方向为金属材料快速成形技术,电话:15514521526,E-mail:panaiqionga@163.com。
