Transient liquid phase bonding of Cu to Cu–W composite using an electron beam energy source

This paper presents an alternative method for fabricating Cu/Cu–W joints suitable for electrical contacts. The process applied to join the Cu to the Cu–W composite involved using an electron beam welding machine operated in conduction mode to form a transient liquid phase at the interface from the melting of a thin Al foil. Analysis of the microstructure of the joints indicated that for optimized processing conditions, Cu–Al intermetallics were not present in the Cu/Cu–W interfacial region. For the joints with such microstructural characteristics, measurement of the mechanical integrity of the interface between the Cu and Cu–W composite indicated that plastic deformation and fracture occurs at the copper side of the assembly.