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采用自行设计的模具对TA1进行二道次等通道径角挤压(ECAP)实验。采用B路径在温度400℃~420℃、挤压速度1mm/min的条件下对边长10mm的方形棒材进行处理,研究挤压变形后微观组织对力学性能的影响。结果表明,工业纯钛经过二道次ECAP变形后,晶粒明显细化,由初始的等轴晶逐渐演变为拉长的晶粒、孪晶交割、板条状组织和细晶组织,且道次增加,板条间距越细小;抗拉强度显著提高,二道次ECAP后的抗拉强度达1240MPa,同时硬度达到319HV,且塑性为16.7%。疲劳极限强度由原始的220MPa提高到280MPa,提高了27.3%。
TA1 was tested with a second-pass ECAP using a self-designed die. A square bar with a side length of 10 mm was treated with a B path at a temperature of 400 ° C to 420 ° C and an extrusion speed of 1 mm / min to study the effect of the microstructure on the mechanical properties after the extrusion deformation. The results show that after two passes ECAP deformation, the grain size of the industrial pure titanium is obviously refined and the initial equiaxed grains gradually evolve into elongated grains, twin delivery, lath and fine grain structure, The smaller the spacing of the slats was, the more the tensile strength was increased. The tensile strength of ECAP after the second pass reached 1240MPa, while the hardness reached 319HV and the plasticity was 16.7%. The fatigue ultimate strength increased from the original 220MPa to 280MPa, an increase of 27.3%.