2005 Volume 23 Issue 2 Pages 296-301
Diffusion bonding and explosive welding of oxide dispersion strengthened silver (ODS-Ag), which is one of electric contact materials, to copper (Cu) have been conducted to compare their interfacial microstructures and bonding strength. The diffusion bonding was carried out at 973 K for 3.6 ks to achieve solid state bonding. Defects like void were observed at the interface in the diffusion bonded ODS-Ag/Cu joint. It is considered that insufficient contact at the interface is responsible for the formation of the defect. The shear strength of this joint was less than 40 MPa and far inferior to that of Ag/Cu joint produced under the same condition. On the other hand, the explosively welded joint had no defects in the collision interface. Its bonding strength exceeded that of the diffusion bonded Ag/Cu joint, and was about four times as high as that of the ODS-Ag/Cu joint fabricated by diffusion bonding. From the results of TEM observations, microstructural aspects of the ODS-Ag in the vicinity of the collision interface appear to be similar to those observed before bonding. This suggests that the characteristics of the ODS-Ag as a electric contact material are retained even after the bonding treatment. Therefore, the solid state bonding with momentary high pressure such as explosive welding is suited to the bonding method for the ODS-Ag materials.
