(1. 哈尔滨工业大学 金属精密热加工国家级重点实验室，哈尔滨 150001；
2. 北京航星机器制造有限公司，北京 100013)
摘 要: 对Ti-22Al-27Nb合金四层结构件SPF/DB组合工艺进行试验研究，对Ti-22Al-27Nb合金的超塑性能及扩散连接性能进行探究。拉伸实验表明，当变形温度为960 ℃、应变速率为1×10-4 s-1时，材料伸长率达到最大，为230%。对温度、保温时间和扩散压力对Ti-22Al-27Nb合金接头质量的影响进行研究，结果表明Ti-22Al-27Nb合金扩散连接的最佳工艺参数为(960 ℃，10 MPa，2 h)。根据高温拉伸试验结果，利用有限元模拟软件对中空四层结构件超塑成形过程进行模拟。通过SPF/DB组合工艺成形得到外观质量良好的Ti-22Al-27Nb合金中空四层结构件，成形构件壁厚分布均匀。
关键字: Ti-22Al-27Nb；扩散连接；超塑成形；四层结构
（1. Harbin Institute of Technology, National Key Laboratory for Precision Hot Processing of Metals, Harbin 150001, China;
2. Beijing Hangxing Machine Manufacturing, Beijing 100013, China）
Abstract:The hollow four-layer structure of Ti-22Al-27Nb alloy was fabricated by SPF/DB process. The characteristics and mechanism of Ti-22Al-27Nb alloy with respect to superplasticity and diffusion bonding were investigated. Tensile tests show that the optimal elongation of tensile specimens is 230% at the temperature of 960 ℃ and the strain rate of 1×10-4 s-1. Effect of the bonding pressure, bonding temperature and bonding time to determine the microstructure and mechanical properties of diffusion bonding joints was investigated, and the optimum bonding parameters are (960 ℃, 10 MPa, 2 h). Through the finite element simulation, it could be found that the SPF/DB process of hollow four-layer structure is feasible. The hollow four-layer structure of Ti-22Al-27Nb alloy is manufactured, showing that the thickness distribution of the bonding area is uniform.
Key words: Ti-22Al-27Nb; diffusion bonding; superplastic forming; four-layer structure
