Microstructure and Properties of Phosphorus Bronze/Brass Joints Produced by Resistance Projection Welding

In this work, we fabricated lap joints between embossed projection phosphorus bronze and flat brass through resistance projection welding (RPW). The experimental results indicated that the bronze projection moves into the softer brass without being deformed during the welding process. The tensile shear loads of the joint reached a maximum value of 273.6 N at a welding current of 5.5 kA. Under this circumstance, a reaction layer, including a columnar crystal solidification layer and a diffusion layer, is formed at the interface beside the boundary of bronze. The EDS line scan shows an elemental transition diffusion layer of about 1.5 & mu;m between the H62 brass columnar crystal and XYK-6 phosphorus bronze. The fracture occurred on the XYK-6 side, passing through the bump instead of the welding interface, resulting in intactness of the welding interface. The results revealed that resistance projection welding is an effective method for welding copper alloys, suggesting the bright prospects of this technology in welding electrical parts.

Automated summary

Lap joints between embossed projection phosphorus bronze and flat brass were successfully fabricated through resistance projection welding (RPW). The bronze projection moved into the softer brass without deformation during welding. Tensile shear loads of the joint reached a maximum value of 273.6 N at a welding current of 5.5 kA. A reaction layer, consisting of a columnar crystal solidification layer and a diffusion layer, formed at the interface beside the boundary of bronze. An elemental transition diffusion layer of about 1.5 μm was observed between H62 brass and XYK-6 phosphorus bronze. Fracture occurred on the XYK-6 side, passing through the bump instead of the welding interface, resulting in intactness of the welding interface. The results indicate the effectiveness of resistance projection welding as a method for welding copper alloys, suggesting its promising prospects in welding electrical parts.