TA15四层板结构超塑成形/扩散连接技术研究

Research on Superplastic Forming/Diffusion Bonding for Four-Sheet Structure of TA15 Titaninum Alloy

进行了TA15合金超塑拉伸试验,在温度920℃和应变速率5.25×10^(-4)s^(-1)时,TA15合金的最大延伸率约为1100%,其应变速率敏感性指数约为0.57。在较佳超塑变形条件930℃和应变速率5.25×10^(-4)s^(-1)附近,TA15合金的超塑本构方程为σ=949ε·^(0.55)。对TA15四层板结构超塑成形过程进行了有限元分析,获得了压力p-时间t曲线。在T=930℃和应变速率5.25×10^(-4)s^(-1)下,成功进行了TA15四层板结构SPF/DB成形试验,试验件的整体质量良好,无沟槽等缺陷,金相组织观测表明,TA15四层SPF/DB试验件扩散连接质量优良。

The optimal superplastic deformation condition of TA15 titanium alloy is determined by tensile test. The maximum elongation of 1100% could be obtained at 920℃ at strain rate of 5.25×10^（-4）s^（-1） and its strain-rate sensitivity index is 0.57. The constitutive equation of TA15 titanium alloy is σ = 949 ε·^（0.55） at 920℃ at strain rate of 5.25×10^（-4）s^（-1）. The processes of superplastic forming/diffusion bonding（SPF/DB） of four-sheet structure of TA15 are simulated to obtain the pressure-time curve by the finite element Marc software. The forming test of TA15 titanium alloy four-sheet structure is conducted successfully at 930℃ at strain rate of 5.25×10^（-4）s^（-1）. No grooves or other defects are found on the surface of the test pieces. According to metallographic observational, the diffusion bonding is in good quality and attained the metallurgical connection.