Review of Experimental and Computational Investigations into Laser Impact Welding

Abstract Laser Impact Welding (LIW) is a specialized, solid-state method for joining small metallic sheets or foils at the scale of a few millimeters using high-powered laser pulses. Unlike traditional welding methods, LIW avoids bulk melting, thereby minimizing the occurrence of associated defects and distortions. Its working mechanism involves laser-induced vaporization of a thin film to create a high-pressure plasma that propels a flyer material at high speed into a target material, creating a strong mechanical bond upon impact. The process is ideal for joining two metals having vastly different thermal properties, such as aluminum, steel, and copper, stemming from the ability to create durable mechanical bonds whose strength is reinforced by unique, wave-like, interfacial material penetrations. Accordingly, LIW is particularly attractive for electronics, aerospace, and automotive industries, wherein lightweight and strong joints or connections involving dissimilar materials are needed at a small (millimeter) scale. This review article explores the state of both experimental and computational research into LIW, with an emphasis on recent efforts to further understand the process mechanisms and to simulate the process in order to aid its practical implementation. Discussed are new insights into how the material properties, laser parameters, physical set-ups, and resulting shockwave dynamics influence the bond quality. Also discussed is continuing research on LIW, to render it more practical for widespread industrial use, and to adapt it into a novel solid-state additive manufacturing method.