Laser Brazing of Dissimilar Joint of Austenitic Stainless Steel and Pure Copper

Abstract

In many industries, there are applications that require the joining of stainless steel and copper components; therefore, the welding of dissimilar stainless steel/copper joints is a common process. For this investigation, the optimal brazing conditions and suitable filler metals for laser brazing of stainless steel/copper lap joints were studied. Tensile shear force increases with increases in the laser spot diameter or in the laser irradiation angle, which is associated with increased bonding width; however, as bonding width approaches 2 mm, tensile shear force reaches a saturated value due to fracturing at the HAZ of the Cu base plate. In order to obtain joints with high tensile shear strength, laser brazing was optimized by using Cu-Si-based filler metal under the following conditions: laser power: 4 kW; spot diameter: 3mm; laser irradiation angle: 80 degrees; irradiation position shift: 0.6 mm; brazing speed: 0.30 m/min; and filler metal feed speed: 0.30 min. Concerning filler metals, it was found that the Ni-Cu type showed relatively large tensile shear force even at high welding speeds in comparison with those of the Cu-Si, Cu, Cu-Ni, Ni-Cu and Ni types, respectively.

Investigation of Single-Pulse Laser Welding of Dissimilar Metal Combination of Thin SUS303 SS and Cu

“…Suga et al [13] presented a study on the laser welding of SS-Cu lap weldments, focusing on the identification of favorable filler materials and optimal brazing parameters. This joining method demonstrated efficiency and effectively mitigated the occurrence of cracks and other defects.…”

Pulsed-Electric-Current Bonding of Oxygen-Free Copper and Austenitic Stainless Steel

“…However, it is difficult to weld pure copper and stainless steel due to the differences between their melting points and thermal conductivities as well as the low solid solution limit of copper compared to stainless steel. 1,2) Therefore, the solid-phase bonding method without melting is considered to be a suitable technique for joining these metals. Solid-state bonding methods mainly include diffusion bonding, friction welding, hot pressure welding, cold pressure welding, explosion pressure welding and gas pressure welding.…”