Mechanical Properties of Laser Welded Joint of Copper and Steel Dissimilar Metals

In this research project, copper and stainless steel were connected by two laser welding methods: straight seam welding and swing welding. Then, electronic tensile test machine, X-ray diffractometer, scanning electron microscope and metallographic microscope were used to analyze the tensile properties, macroscopic and microscopic structure morphology and phase of the welded joint. Based on the experimental results, we determined that the strength of the straight seam welded joint was higher. Because of the intermetallic compound near the weld in the swing welding process, it leads to stress concentration, crack cracking and strength reduction. In addition, the oscillating laser beam also leads to the disorderly direction of columnar crystal and coarse structure, which makes the joint strength decrease