Spatter elimination mechanism and criterion for adjustable ring-mode laser welding of aluminum alloy

Abstract

Adjustable-ring-mode laser welding has emerged as a promising technique for spatter mitigation in highly reflective aluminum alloy joints, yet the underlying physical mechanisms remain unclear. This study reveals the spatter suppression mechanism enabled by ring-mode laser. The ring-mode laser preheats the leading edge of the melt pool, avoiding sharp fluctuations of the laser absorption rate, and stabilizing the eruption of vapor plume to achieve spatter suppression. A quantitative relationship model is established to correlate preheating temperature with key process parameters, including total laser power, ring power share, and welding velocity. Furthermore, a novel processing window for effective spatter suppression is proposed, with the optimal preheating temperature range identified between the melting point and boiling point of the base metal. Based on these findings, the criteria for selecting spatter-free process parameters is developed. Experimental validation confirms significant spatter reduction when operating within the proposed parameter range. This work provides fundamental insights into the laser-material interaction mechanisms and offers practical guidelines for high-quality welding of highly reflective alloys, advancing both theoretical understanding and industrial applications in laser welding technology.