铝合金7075马鞍外形蠕变时效成形数值模拟及试验

FEM analysis and experimental study on the creep age forming for components with saddle contour of Aluminum alloy 7075

蠕变时效成形技术是利用金属的蠕变特性,将成形与时效同步进行的一种成形方法。文章针对铝合金7075T651进行温度在160℃下的蠕变拉伸试验,基于蠕变试验数据,采用非线性最小二乘法确定了7075T651铝合金蠕变本构方程中的材料常数,并应用有限元软件通过编写蠕变子程序,建立了该材料的蠕变时效成形过程有限元模型。针对马鞍典型外形零件进行蠕变时效成形-回弹分析,就成形过程中的应力应变分布进行分析。在相应条件下进行了蠕变时效成形试验,并对模拟结果进行验证。结果表明,采用该本构方程,可以较好的对蠕变时效成形过程及回弹进行模拟预测。

Creep age forming （CAF） is a combined forming and ageing heat treatment process utilizing metallic creep characteris- tic. In this paper, creep ageing tests are carried out for a range of stress levels at 160℃, which is the typical period for CAF process of Aluminum alloy 7075T651. Based on experimental results, the material constants of the constitutive equations are de- termined by non-linear least squares fitting methods. The creep age forming of components with saddle contour are analyzed by u- sing FE software ABAQUS through the user-defined subroutine CREEP. The distribution of the stress and the strain are also an- alyzed in this paper. Finally, experimental research is preformed to validate the FEM results. It is found that the creep age form- ing process and springback can be predicated based on the FEM model.