(1. 宁夏东方钽业股份有限公司 钛材分公司，石嘴山 753000；
2. 西北工业大学 材料科学与工程学院，西安 710072)
摘 要: 对Ti-662钛合金棒材进行锻造、固溶及时效处理，利用光学显微镜、SEM 及力学性能试验对该合金3种状态下的显微组织和力学性能进行研究。结果表明：Ti-662钛合金锻棒的组织为初生等轴α+β转变组织，其强度较高，伸长率较大，抗拉强度达到1 149 MPa，伸长率为16.5%；合金经固溶热处理后初生α相明显增多，主要组织为初生α相、马氏体转变的α′相和亚稳β相，合金强度和伸长率有所降低，但断面收缩率有所提高，说明固溶处理有一定的软化作用；经固溶处理后的棒材在时效处理过程中，亚稳态组织析出细小弥散的次生α相，使合金强度明显强化，塑性略有降低，且随着时效温度的升高，强化效果下降，塑性随之提高。
关键字: Ti-662钛合金；棒材；显微组织；性能
（1. Titanium Product Plant, Ningxia Orient Tantalum Industry Co., Ltd., Shizuishan 753000, China;
2. School of Materials Science and Engineering, Northwestern Polytechnical University, Xi’an 710072, China）
Abstract:The microstructure and properties of Ti-662 alloy under three conditions were investigated by using optical microscopy (OM), scanning electron microscopy (SEM) and measurements of mechanical properties for the bars processed by forging, solution and aging treatment. The results show that the as-forged microstructures of Ti-662 alloy bars are fine isothermal primary α and transition β phases, the strength and elongation are higher, the tensile strength and elongation of the alloy are 1 149 MPa and 16.5%, respectively. After solution heat treatment, the quantity of primary α phase of the alloy increases significantly, and the microstructures are mainly composed of isothermal primary α, martensite α′ and metastable β phases. The strength and elongation decrease, but the reduction of area increases, which indicate that solution treatment has a softening effect. Fine dispersion secondary α phase precipitates from the metastable structures after solution and in aging process, and the alloy can be strengthened significantly with slightly reduced plasticity. With the increase of the aging temperature, the strengthening effect reduces, and the plasticity increases.
Key words: Ti-662 titanium alloy; bar; microstructure; properties
