Assessment of Ttensile-Shear and T-Peel Strengths for Cu-STS 304 Dissimilar Overlap Welded Joints using Single-Mode Fiber Laser with High Welding Speeds

Abstract

This study focused on the mechanical and metallurgical properties of Ni-coated pure copper (0.2 mm thick) and stainless steel 304 (0.4 mm thick) dissimilar joints fabricated using single-mode laser welding. Overlap and T-peel welded joints were produced using different welding parameters, such as the laser power and speed. The laser-welded specimens were tested by tensile tests of the weldments, optical metallography, and chemical composition examination of the intermediate layer using energy dispersive X-ray spectroscopy (EDS). The welded joint configuration showed the largest influence on the failure strength. The tensile-shear strengths were more than 3.7 times higher than the T-peel strengths. The scanning electron microscopy and EDS analyses confirmed heterogeneity of the elemental composition across the welded joint interface, regardless of the welding parameters, with minimal occurrence of hot cracks within the welds.