Abstract
The application of powder interlayers to solid-state diffusion bonding was investigated. Base materials used in this investigation were pure Cu, Fe and Ni. Interlayer materials were also Cu, Fe and Ni powders. The bonding was carried out by hot pressing at bonding temperatures of 573-973K and bonding pressures of 7 or 100MPa in vacuum. The cross section of the bonded specimens obtained was observed by optical microscope and SEM. The bonding strength of the specimens was measured using a shearing test. The main results obtained were as follows : (1) When the base and powder interlayer materials are the same, the strength of the diffusion bonded powder interlayer samples was higher than that of direct bonded samples. (2)When the base and powder interlayer materials are different, the strength of diffusion bonded powder interlayer samples was found to be high when the two components are well soluble and low when they are not. (3)When the green density of the powder interlayers was low, the bonding strength of the diffusion bonded powder interlayer samples was below that of direct bonded samples, This is thougth to be due to the sintering shrinkage of powder interlayers during bonding.
