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采用两通道夹角Φ=120°,外圆角ψ=20°的模具,在道次间未退火的条件下实现TA1纯钛BC方式8道次室温ECAP(Equal Channel Angular Pressing)变形,制备表面光滑无裂纹的变形试样。研究纯钛室温ECAP变形组织结构的演变和特征,测定变形试样的力学性能。结果表明:随着室温ECAP变形道次的增加,原始粗大的α相等轴晶由最初几道次形成的板条和孪晶经过自身和相互交割形成亚晶,以及剧烈变形形成的位错胞状结构,通过位错的相互作用和重组逐渐演变成大角度晶界的超细晶等轴组织。获得平均晶粒尺寸约200nm的TA1纯钛试样,其屈服强度和抗拉强度分别由275和407MPa提高到710和791MPa,并保持较高的塑性,延伸率为19.0%。
TA1 pure titanium BC 8-way room temperature ECAP (Equal Channel Angular Pressing) deformation was achieved by using a two-channel mold with Φ = 120 ° angle and ψ = 20 ° external angle without annealing between passes. Smooth, crack-free deformed specimens. The evolvement and characteristics of the deformable microstructure of pure titanium ECAP at room temperature were studied, and the mechanical properties of deformed samples were measured. The results show that with the increase of ECAP deformation at room temperature, the original coarse α-equiaxed axons form subgrains through their own and mutual delivery through the first few passes, as well as dislocation cell structures formed by violent deformation , Through the dislocation of the interaction and reorganization gradually evolved into large-angle grain boundary ultrafine crystal equiaxed organization. The yield strength and tensile strength of TA1 pure titanium samples with average grain size of about 200 nm were increased from 275 and 407 MPa to 710 and 791 MPa, respectively. The high plasticity was maintained and the elongation was 19.0%.