论文部分内容阅读
使用ER5356焊丝,对2.7 mm厚的7075-T6高强铝合金进行了CMT焊接试验,通过光学显微镜、扫描电镜和能谱仪对接头的显微组织及断口形貌进行了分析。结果表明,焊缝成型美观,明显焊透,无气孔等缺陷。焊缝区组织主要是α固溶体和T相(AlZnMgCu)组成,热影响区存在GP区。焊缝区的硬度最低,约为70～80 HV0.1,从焊缝边缘到母材,显微硬度逐渐增加,距离焊缝边缘5 mm处存在软化区。焊接接头拉伸断裂于熔合区,为韧性断裂,接头的抗拉强度为354 MPa,约为母材的61%。
Using ER5356 welding wire, CMT welding test of 2.7mm thick 7075-T6 high strength aluminum alloy was carried out. The microstructure and fracture morphology of the joint were analyzed by optical microscope, scanning electron microscope and energy dispersive spectrometer. The results show that the weld is handsome in appearance, obviously penetrated and without pores. Weld zone organization is mainly α solid solution and T phase (AlZnMgCu) composition, heat affected zone exists GP zone. The hardness of the weld zone is the lowest, about 70-80 HV0.1. From the weld edge to the base metal, the microhardness gradually increases and there is a softening zone at 5 mm from the weld edge. Tensile fracture welded joints in the weld zone, ductile fracture, joint tensile strength of 354 MPa, about 61% of the base metal.