钛合金超塑性成形过程的数值模拟

Numerical Simulation of Super plastic Forming Process of Titanium Alloy

以TC4合金层板结构的超塑性成形过程为研究对象,采用有限元软件MARC模拟计算了TC4合金宽弦空心夹芯结构的超塑性成形过程。分别分析了应变速率敏感指数、目标应变速率及扩散连接宽度等参数对贴模过程及壁板厚度分布的影响。结果表明:当应变速率敏感指数较大时,夹芯结构会发生沿纵向挤出延伸变形;当目标应变速率为10-3时,材料表现出较佳的超塑性性能;而扩散连接宽度的大小对超塑性成形后板材壁厚分布的均匀性有一定影响。通过控制最大应变速率的方法,提取出了最优化的压力时间曲线。研究结论可为钛合金空心夹芯结构件的超塑性成形提供理论参考。

Taking the super-plastic forming（SPF） process of the three plate structure as the research object, the super-plastic forming process of TC4 wide-chord hollow structure was simulated by using finite element software MARC. The effects of the strain rate sensitivity index, the target strain rate and the diffusion bonding width on the coating process and the thickness distribution of the pane] were studied. The results show that the wide-chord hollow structure deform along the longitudinal extension of extrusion, when the strain rate sensitivity index is larger, and the struture shows better performance of super plastic forming, when the strain rate is around of 10-3. Meanwhile, the diffusion bonding width has a certain influence on the uniformity of the sheet thickness distribution after the super plastic forming. The optimal pressure time curve is obtained by controlling the maximum strain rate. The results of the study can provide theoretical reference for super-plastic forming of titanium alloy wide-chord hollow structure.