【摘要】 采用金相显微镜、透射电镜和X射线衍射仪等研究Ti-15-3合金板材在交叉换向轧制过程中的组织演变规律和力学性能变化。结果表明:经过5道次换向冷轧、厚度方向总变形量为80%的Ti-15-3合金板中,形成了间隔的纤维带状组织,其内部形成了200 nm左右的亚微米级晶粒。纤维组织的形成过程分为3个阶段,第一阶段,在个别晶粒内部形成局部剪切带;第二阶段,拉长带状组织内部平行排列的剪切带相互交叉并逐渐碎化;第三阶段,形成间隔的纤维组织,其内部晶粒为亚微米级。在轧制变形中,经1道次变形后,抗拉强度迅速升高到949 MPa,随后抗拉强度最终缓慢增加至1 021 MPa。固溶态合金以每道次30%的压下量经过5道次换向冷轧并于450℃时效4 h后,抗拉强度为1 646 MPa。更多还原

【Abstract】 The microstructure evolution and mechanical properties of Ti-15-3 alloy during cold rolling were investigated by optical microscopy,transmission electron microscopy and X-ray diffractometer.The results show that fibrous microstructure in which grains are refined to about 200 nm was formed in the sheet of Ti-15-3 alloy with total thickness reduction of 80% after five passes cross cold rolling.The structure formation may be divided into three steps: firstly,the partial shear bands form in some grains;secondly,the shear bands of different direction within the banded structure cross and refine;thirdly,the fibrous microstructure with sub-micron grains forms.During cold rolling,the ultimate strength of alloy increases sharply to 949 MPa after 1 pass and slightly to 1 021 MPa in the following passes.After 5 passes cross cold rolling with cold rolling rate of 30% per pass and aging at 450 ℃ for 4 h,the ultimate strength of alloy can be increased to 1 646 MPa.更多还原