铝合金-碳钢管的磁脉冲变形连接

摘要

采用带集磁器线圈装置对3A21铝合金-20钢管件进行磁脉冲连接,并对连接接头的力学性能和微观结构进行测试和观察.结果表明,在电压为15 kV、径向间隙为1.2～1.4 mm和搭接区锥角为3°～7°的条件下可获得冶金连接接头.连接接头由宽度不均匀的过渡区、两母材及其与母材连接的界面构成.连接界面呈微波状形貌,过渡区发生基体元素Fe和Al的互扩散.过渡区由Fe-Al金属间化合物构成,并存在微裂纹和微孔洞等缺陷；其显微硬度明显高于邻近母材的显微硬度.%The magnetic pulse joining (MPJ) between 3A21 aluminum alloy and steel 20 tubes was experimentally investigated with a solenoid coil assisted by a field shaper.The mechanical properties and microstructure of MPJ joints were tested and observed.The results show that the metallurgical joints can be obtained at a voltage of 15 kV,a radial gap of 1.2-1.4 mm,and a slope angle of 3°-7° in the lapping area.The joint comprises a transition zone with different widths,two matrix metals and two interfaces between the zone and the two metals.The interface presents a typical wavy pattern and mutual diffusion of Fe and Al elements happens in the zone.The transition zone is composed of Fe-Al intermetallics,micro cracks and micro pores.The microhardness of the transition zone is much higher than that of the matrix metals.