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针对8 mm厚的7A52铝合金采用搅拌摩擦焊(FSW)进行焊接试验,研究了其焊接接头的显微组织及力学性能。结果表明:焊接接头宏观上呈V字状,焊核区组织为细小的等轴晶,且焊核区底部的晶粒比焊核区顶部和中部的晶粒更为细小,热影响区组织稍有粗化现象,前进侧和后退侧的热力影响区组织均较焊核区组织粗大;焊接接头显微硬度分布呈现出“W”形变化,焊接接头的平均抗拉强度为452 MPa,达到了母材抗拉强度的89%,断裂位置均发生于热影响区及热力影响区的过渡区,焊接接头的断裂模式为韧性断裂,电化学腐蚀形貌以点蚀和晶间腐蚀为主。
The 7A52 aluminum alloy with 8 mm thickness was welded by friction stir welding (FSW), and the microstructure and mechanical properties of the welded joint were studied. The results show that the welded joints are V-shaped macroscopically and the microstructure of the weld zone is fine equiaxed. The grains at the bottom of the weld zone are finer than those at the top and middle of the weld zone. The microstructure of the HAZ And the microstructure of the heat-affected zone on both the forward side and the backward side is thicker than that of the nugget. The microhardness distribution of the welded joint shows a “W” shape change. The average tensile strength of the welded joint is 452 MPa, Reached 89% of the base metal tensile strength, the fracture location occurred in the transition zone of heat affected zone and heat affected zone, the fracture mode of the welded joint is ductile fracture, the electrochemical corrosion morphology is mainly pitting and intergranular corrosion .