(哈尔滨工业大学 材料科学与工程学院，哈尔滨 150080)
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。
关键字: Ti-15-3合金；冷轧；时效；力学性能
Ti-15-3 alloy during cold-rolling
（School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150080, China）
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.
Key words: Ti-15-3 alloy; cold rolling; aging; mechanical properties
