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室温下,采用复合细化(ECAP+冷轧+旋锻)工艺,制备出平均晶粒尺寸约为180 nm的超细晶工业纯钛,其抗拉强度高达870 MPa。利用纳米压痕仪对超细晶工业纯钛以恒加载速率/载荷的方式进行测试实验,通过测定压头保载阶段的压入位移和材料的硬度值计算得出室温蠕变速率敏感指数m值。结果表明:超细晶工业纯钛由于晶粒明显细化,晶界数量增多,晶界长度增加,位错增殖,在室温下表现出优良的抗蠕变能力,适合在压力环境下长期工作,其蠕变机理主要为蠕变位错机理。室温蠕变速率敏感指数m值与加载条件无关,主要由材料的微观组织决定。
At room temperature, ultrafine grained industrial pure titanium with an average grain size of about 180 nm was prepared by composite refinement (ECAP + cold rolling + swaging) at room temperature with a tensile strength as high as 870 MPa. The nano-indenter was used to test the ultrafine-grained industrial pure titanium at a constant loading rate / load. The creep rate sensitivity index at room temperature was calculated by measuring the indentation displacement and the hardness of the material at the loading stage. value. The results show that ultrafine grained industrial pure titanium has good creep resistance at room temperature due to the grain refinement, the increase of grain boundary, the increase of grain boundary length and the dislocation. It is suitable for long-term working under pressure environment, The creep mechanism is mainly creep dislocation mechanism. Room temperature creep rate sensitive index m value has nothing to do with the loading conditions, mainly determined by the microstructure of the material.