Magnetic field edge-effect affecting joint macro-morphology in sheet electromagnetic pulse welding
Chengxiang Li, Yan Zhou, Xin Shi, Zhigang Liao, Jian Du, Ting Shen, Chenguo Yao
Abstract
Electromagnetic pulse welding (EMPW) is an environmentally friendly and advanced manufacturing technology. Researches find the macro-morphology of EMPW joint of sheets presents a multilayer ellipse. The EMPW experiments of Al-Cu sheets and Al-Mg sheets were carried out, both the macro-morphology and the micro-morphology showed there were collision zone, bonding zone and bonding affecting zone in the joint, presenting multilayer elliptical morphology, which was independent of material. The welded seam was in the bonding zone. The 3D multiphysics simulation results also showed that the distribution of the plastic deformation of Al sheet, Lorentz force, induced eddy current and magnetic flux density at the welded joint were all elliptical, and they presented a multilayer elliptical continuous equivalent distribution surface due to the difference of amplitude. The magnetic field edge-effect affects the distribution of the magnetic flux density, and the non-uniform distribution produces the multilayer elliptical macro-morphology, which causes the induced eddy current, Lorentz force and the deformed area of the aluminum alloy plate to be the elliptical shape. Therefore, the macro-morphology of EMPW joint of sheets is a multilayer ellipse. This work may provide theoretical support for the performance improvement of the EMPW technology.