盒形件超塑成形过程中材料流动规律的数值模拟与实验

利用有限元软件MSC.Marc2010对钛合金盒形件超塑成形过程进行了有限元模拟,控制目标应变速率,得到优化的压力-时间曲线,并据此进行实验研究,沿实验曲线分别加载至6个不同的标定压力值(分别为0.5,1.0,1.5,2.0,2.3和2.5MPa)得到成形过程中的零件。测量6个实验零件的外形轮廓和厚度,并分别与相对应的模拟结果进行对比,验证实验与模拟的一致性,并分析整个成形过程中的材料流动规律,得出在自由胀形、底部贴模、充填圆角3阶段盒形件不同区域的应力、应变和变薄率分布,为复杂零件的超塑成形工艺的制定奠定了一定的理论基础。

Numerical Simulation and Experiment on Material Flow Regulation During Superplastic Forming Process of Box-Shaped Part

The superplastic forming process of the box-shaped part is simulated by using finite element software MSC.Marc2010 to optimize the curve of pressure-time under the control of the target strain rate.The fitted curve used in the experiment is based on the simulated pressure-time(p-t) curve.The six parts are obtained along the same optimal experiment p-t curve at six selected pressure respectively(0.5,1.0,1.5,2.0,2.3 and 2.5 MPa).By measuring the outline and thickness of the six parts,the experimental result is compared with the numerical simulation result to verify if they agree with each other,and the material flow regulation can be analyzed.The distribution results of stress,strain and reduction rate of the three periods of free bulging,closing up to the cavity and corner fiuing are obtained,which lays the theoretical foundation for the superplastic forming process design of complex parts.