异种金属摩擦焊后电场热处理组织与扩散行为

采用电子探针线扫描等试验技术研究了强电场对T2紫铜和1Crl8Ni9Ti不锈钢摩擦焊接头焊后退火显微组织及其主要合金元素扩散行为的影响。结果表明：外加电场加快了焊合区金属的再结晶进程，提高了晶粒长大速度，增大了晶粒尺寸，且使退火孪晶数量增多，其中负电场(试件接电源负极)的作用最为明显；此外，紫铜与不锈钢摩擦焊接头焊后电场退火过程中，主要合金元素Cu与Fe在焊合区的扩散区比常规热处理时要宽，且扩散区宽度随电场强度数值的增大而增大。其中，负电场使摩擦焊接界面扩散区宽度增大更为明显。

Effect of External Electric Field on Microstructure And Diffusion Behavior of Friction Welding Joint of Dissimlar Materials During Post Weld Annealing Treatment

The friction welding joint of T2 copper and 1Cr18Ni9Ti stainless steel was employed to study the effect of post weld annealing treatment in the presence of electric field on the microstructure and diffusion behvior of the joint by electronic probe and optical microscope. The results show that electric field promotes the recrystallization of the weld metal, enhances the growth of recrystallization grains and increases the number of annealing twin. In addition, the diffusion zone of Fe and Cu widens in the presence of electric field. Moreover, the wider diffusion zone of the friction welding joint after annealing treatment with the increase of electric field intensity is found, and the electric field has greater influence on the diffusion distance when the specimen is connected to the cathode of the power supply.