摘要
在室温下经4道次等径弯曲通道变形(ECAP)及旋锻复合变形制备超细晶纯钛。利用透射电子显微镜、拉伸试验测试和显微硬度测试等方法对比研究了旋锻对ECAP变形纯钛的显微组织和力学性能的影响。结果表明:ECAP变形后形成宽度约为400 nm的板条组织,板条边界位错密度明显较高,硬度值急剧增加;旋锻使ECAP剪切变形形成的板条组织消失,晶粒显著细化、晶界逐渐清晰,获得平均晶粒尺寸约为200 nm的等轴状超细晶组织,旋锻变形后的组织更均匀,位错密度较低,硬度值略有下降;旋锻变形使ECAP变形纯钛屈服强度和抗拉强度明显增大,增幅分别为26.3%和17%,塑性降低,伸长率约为12.3%。
Ultra-fine grained pure titanium was prepared by composite deformation of equal channel angular pressing(ECAP)for four passes and rotary swaging(RS)at room temperature.The effect of RS on microstructure and mechanical properties of pure titanium processed by ECAP was investigated by transmission electron microscopy(TEM),tensile test and microhardness test.The results show that the deformation of ECAP forms a slab structure with width of about 400 nm.The dislocation density of the slab boundary is significantly higher,and the hardness of the slab boundary increases sharply.The slab structure formed by ECAP shearing deformation is eliminated by RS,the grains are remarkably refined,and the grain boundaries become clear.The equiaxed ultra-fine grained microstructure with an average grain size of about 200 nm is obtained,microstructure after RS is more uniform,the dislocation density is lower,and the hardness value decreases slightly.Due to RS deformation,the yield strength and tensile strength of the pure titanium processed by ECAP increase by 26.3%and17%,respectively,the plasticity of the pure titanium processed by ECAP decreases,and the elongation is approximately 12.3%.
作者
柳奎君
刘晓燕
杨西荣
刘雅洁
董卓
王倩
吕凡凡
LIU Kui-jun;LIU Xiao-yan;YANG Xi-rong;LIU Ya-jie;DONG Zhuo;WANG Qian;LU Fan-fan(School of Metallurgical Engineering,Xi'an University of Architecture and Technology,Xi'an 710055,China)
出处
《塑性工程学报》
CAS
CSCD
北大核心
2020年第1期90-95,共6页
Journal of Plasticity Engineering
基金
国家自然科学基金资助项目(51474170)
国家级大学生创新训练项目(20190703054)
关键词
等径弯曲通道变形
旋锻
超细晶钛
微观组织
力学性能
ECAP
rotary swaging
ultra-fine grained pure titanium
microstructure
mechanical properties
