电动汽车用7075铝合金搅拌摩擦焊性能研究

为了解决电动汽车电池能量密度不达标问题,电池壳采用7075铝合金代替6系铝合金,研究7075铝合金焊接性能,分别对7075和7075-T6进行搅拌摩擦焊,及对7075焊后T6热处理,并且焊后进行力学性能对比分析及显微组织观察。得出结论:未经热处理的7075铝合金搅拌摩擦焊缝系数可达0.96;热处理后焊缝抗拉强度有所提升,但焊前热处理强度提升明显;焊前热处理和焊后热处理的焊缝抗拉强度与转速/焊接速度具有相同的变化趋势,均在转速1600r/min,焊接速度600/min时获得较高抗拉强度。为实际生产过程中7075铝合金的热处理及焊接状态的选择提供参考。

Study on Friction Stir Welding Performance of 7075 Aluminum Alloy for Electric Vehicle

In order to solve the problem of substandard energy density of electric vehicle batteries,7075 aluminum alloy was used instead of 6 aluminum alloy to study the welding performance of 7075 aluminum alloy.Friction stir welding was carried out on 7075 aluminum alloy and 7075-T6,and heat treatment was carried out on T6 after 7075 welding,and mechanical properties were compared and analyzed and microstructure observed after welding.Conclusion:Friction stir weld coefficient of 7075 aluminum alloy without heat treatment can reach 0.96;After the heat treatment,the tensile strength of the weld was improved,but the heat treatment strength before the welding was improved obviously.The weld tensile strength of pre-weld heat treatment and post-weld heat treatment has the same variation trend with the speed/welding speed,both of which obtain higher tensile strength at the speed of 1600r/min and the welding speed of 600mm/min.It provides reference for the heat treatment of 7075 aluminum alloy and the choice of welding state in the actual production process.