TA15钛合金局部减重中空双层结构超塑成形/扩散连接工艺

Superplastic Forming/Diffusion Bonding Technology for Hollow Double Layer Structure of TA15 Titanium Alloy With Local Weight Reduction

在应变速率为0.001 s^(-1)、0.005 s^(-1)、0.01 s^(-1),温度为880℃、900℃、920℃、940℃的条件下对TA15钛合金进行了高温拉伸试验,材料在920℃以上、0.005 s^(-1)以下的延伸率可超过500%,具有优异的超塑性能。计算了TA15钛合金的本构方程及在应变速率为0.005 s^(-1)时,不同温度下的应变敏感性指数m值和材料常数K值。通过超塑成形/扩散连接(SPF/DB)工艺,采用有限元模拟对双层结构件的壁厚分布进行分析,并获得了气压加载压力–时间曲线。在温度为920℃时,采用预镂空面板制得了局部减重的中空双层结构件,最小壁厚为0.31 mm,采用超声波C扫描对零件的扩散面积进行分析,结果表明,焊合率高于95%。

High-temperature tensile tests were performed on TA15 titanium alloy at strain rates of 0.001 s^(-1),0.005 s^(-1),0.01 s^(-1) and temperatures of 880℃,900℃,920℃,940℃.The material exhibits excellent superplasticity with elongation exceeding 500%above 920℃and below 0.005 s^(-1).The constitutive equations of TA15 titanium alloy and the strain sensitivity index m and material constant K values at different temperatures with strain rate of 0.005 s^(-1) were calculated.Finite element simulations were used to analyze the thickness distribution of the double-layered structural component,and pressure–time curves were obtained.At the temperature of 920℃,the hollow double layer structural parts with local weight reduction are made by using pre-hollow panels SPF/DB,the minimum wall thickness is 0.31 mm,the diffusion area of the component was analyzed by ultrasonic C-scan,and the results showed that the bonding ratio is higher than 95%.