Prospects of laser welding technology in the automotive industry: A review

Spatter, the ejection of melt from a weld pool, is a major problem whenever it occurs in a welding process. The ejection of droplets from the weld metal results in a weld with underfill, undercuts, craters, blowholes, or blowouts—all of which can have a detrimental effect on the mechanical properties of the weld. This paper presents a systematic description of the different types of spatter phenomena which occur during laser welding. A categorization system is proposed to facilitate the comparison and combination of research findings on spatter. This should allow researchers in this area to act as a more effective team in future.

Spatter in laser welding

A comparative study on welding temperature fields, residual stress distributions and deformations induced by laser beam welding and CO2 gas arc welding

Gap-free fibre laser welding of Zn-coated steel on Al alloy for light-weight automotive applications

Effects of pulsed Nd:YAG laser welding parameters and subsequent post-weld heat treatment on microstructure and hardness of AISI 420 stainless steel

CO2 laser welding of galvanized steel sheets using vent holes

Welding of 0.05 mm (0.002 inch) thin AA 5052-H19 aluminum samples in lap-joint configuration was conducted autogenously (no filler metal) using dual lasers that included Nd:YAG and diode with a zero inter-beam spacing. The 70-ns pulsed Nd:YAG (1064 nm) laser acted as the welding tool while the continuous wave diode (810 nm) laser with interaction times of 40–120 ms served to improve the light absorption characteristics of aluminum through preheating and oxidation effects. The microstructure, composition, flaws, and hardness of the joint were evaluated by scanning electron microscopy, energy dispersive X-ray analysis, X-ray diffraction, and micro-indentation hardness test. The dual-beam welding technique was also compared with single-beam (Nd:YAG) welding. Results of parametric effects are displayed in the form of processing maps. Deeper penetration, better weld quality (less humping and cutting), and increased hardness were observed in dual-beam welds when compared with single-beam welds. The most astounding result was a nearly 200% increase in hardness over the base metal in dual-beam welding. This can be explained by the oxygen pickup in a dual-beam weld due to longer heating and amorphous microstructure of aluminum oxide as revealed by energy dispersive X-ray spectrum and X-ray diffraction respectively.

Weichiat Chen

Papers

CO2 laser welding of galvanized steel sheets using vent holes

Dual-beam laser welding of ultra-thin AA 5052-H19 aluminum