中文摘要：

通过自制的ZL-2型超强脉冲放电装置对含孔洞缺陷的A356铝合金焊接接头进行了电磁热强化实验，采用金相显微镜对强化前后焊接接头各区域微观组织和孔洞附近组织进行了对比分析，利用微机控制万能实验机对强化前后试件的拉伸性能进行了测试，并用SEM扫描电镜对拉伸断1：2进行了分析，采用型号为FM-700的显微硬度计对强化前后试件进行了硬度测试。结果表明：合适的脉冲电流有较好的晶粒细化效果，强化后的焊接接头各区域组织得到细化，焊接接头的力学性能得到改善，经脉冲放电后的抗拉强度平均提高了11％，延伸率平均提高了14．2％，且强化后接头的硬度明显较强化前高。

英文摘要：

By a ZL-2 super pulse discharge generator,the welded joints of A356 aluminum alloy with hole defects were discharged by electromagnetic heating. Microstructure of welded joints and the microstructure near the hole were analyzed before and after discharge by metallographic microscope. Tensile property test of specimens was made by microcomputer control universal testing machines. Scanning electron microscope was used to observe the fracture organization. Hardness test was made by FM-700 microhardness tester before and after reinforcement. The results show that the appropriate pulse current has better crystal grain refinement effect. After reinforcement the microstructure of welded joints becomes refining, mechanics property of the welding joints is improved, tensile strength is increased 11% and elongation is increased to 14.2% on average after pulse current experiments, and the hardness of welded joints increases obviously.