5A90 Al-Li合金板材脉冲电流辅助拉深成形

为了解决5A90 Al-Li合金塑性加工困难的问题,通过理论分析与实验测试相结合的方法,对5A90 Al-Li合金板材的脉冲电流加热特性进行了研究。研究发现,10 A·mm~(-2)的脉冲电流可在2 min内将板材加热到300℃。通过单向拉伸试验对5A90 Al-Li合金板材的高温力学性能进行了测试,测试结果表明,300℃时,板材的伸长率可达63.4%。以脉冲电流加热特性和高温力学性能的研究为基础,对板材试验件的成形过程进行了设计,经脉冲电流加热后成形的试验件尺寸精度满足设计要求,且表面质量良好,无裂纹、划伤等缺陷。脉冲电流辅助热成形技术为5A90 Al-Li合金钣金薄壁类零件的塑性加工提供了一条简便、高效的途径。

Pulse current auxiliary deep drawing for Al-Li alloy sheet 5A90

In order to solve the difficulty in producing Al-Li alloy 5A90, the heating characteristics of sheet 5A90 heated by pulse current were studied by the theoretical analysis and experimental test.It is found that the sheet 5A90 can be heated to 300 ℃ in two minutes by pulse current of 10 A?mm-2.Then, the mechanical properties of sheet 5A90 at high temperature were tested by uniaxial tensile test.The results show that the elongation of sheet 5A90 can reach 63.4% at 300 ℃.Furthermore, based on the study of heating characteristics and mechanical properties, the forming process of workpiece 5A90 is designed, and the stringer 5A90 is successfully formed by the process of pulse current assisted thermoforming.Finally, the dimensional accuracy of the workpiece meets the design requirements and the surface quality is good without cracks and scratches.The pulse current assisted thermoforming technology provides a simple and efficient way for the forming of Al-Li alloy 5A90 parts with thin-wall.