Mechanisms of the Porosity Formation during the Fiber Laser Lap Welding of Aluminium Alloy

J. Wang, Wuhan Textile University, Wuhan, China C. M. Wang, G. Z. Wang, Huazhong University of Science and Technology, Wuhan, China When joining the aluminum alloys, one of the biggest challenges is the formation of porosity, which deteriorates mechanical properties of welds. In this study, the lap welding was conducted on an aluminum alloy 5754 metal sheets with a thickness of 2 mm. The effects of various laser welding parameters on the weld quality were investigated. The porosity content was measured by X-ray inspections. The key is to control the solidification duration of molten pool. When the solidification duration of molten pool is large enough, more bubbles can escape from the molten pool and less remain as porosity.