5083铝合金壳体超塑胀形加载曲线优化控制

为了改善超塑成形零件的壁厚均匀性问题,优化了有限元软件MARC的加载算法.在每一步长中选取20个应变速率最大的单元,求平均值,并与最佳应变速率对比,获得优化加载曲线.基于有限元分析,选择5083铝合金壳体进行了超塑成形实验.研究结果表明:优化的加载算法使应变速率始终保持在最佳应变速率附近,提高了零件变形严重区域的厚度;避免了在加载过程中由于壁厚不均匀使得裂纹产生,验证了模拟结果的准确性.与MARC默认的加载算法相比,采用优化加载算法能改善零件的壁厚均匀性.

Optimization of pressure cycle for superplastic forming of 5083 aluminum alloy shell

To improve the uniformity of wall thickness of components during superplastic forming, the loading algorithm of commercial software MARC was optimized. Through selecting twenty elements with maximal strain rates and averaging, then comparing with the optimal strain rate, the optimizational loading curve was abtained. Based on finite element analysis, 5038 aluminum alloy shell was employed to superplastic experiment. The simulation results show that the strain rate almost remains at the optimal strain rate by optimizational loading algorithm, and the thickness of severe deformation region of components is also increased. Superplastic forming results show that the production of cracks is avoided with the help of optimizational loading curve. These cracks are produced by the uniformity of wall thickness. Experimental results verify the accuracy of the simulation results. Compared with the loading algorithm of MARC, the uniformity of wall thickness of components can be improved by optimizational loading algorithm.