Enhanced welding efficiency in laser welding of highly reflective pure copper

A critical challenge in laser welding of pure copper and its alloys is low welding efficiency due to high laser beam reflectivity and high thermal conductivity of the materials. In order to improve laser welding efficiency, a copper-based nano-composite material was developed as absorber for laser welding of pure copper and its alloys. The aim of this study is to investigate the influence of applying this copper-based nano-composite absorber in laser welding of pure copper. Welding efficiency and weld quality were compared between laser welding of pure copper with and without this absorber. Metallographic, mechanical, chemical and electrical properties of welds were studied. Experimental results show that laser welding efficiency was significantly increased after applying the copper-based nano-composite absorber. No significant change of weld quality in terms of chemical composition, electrical properties and hardness was observed. Compared to as-received pure copper coupons, the tensile strength of the welds was 88% of that of the base material.