Effect of Surface Asperity on Diffusion Bonding

Abstract

The effect of surface asperity (mainly ridge height H, ridge wavelength W and aspect ratio H⁄W) on the diffusion bonding process was investigated. Ridge wavelength W as well as ridge height H have a significant effect on the properties of the diffusion bonded joint. The percent of bonded area increased with decreases in W and H. When the ridge height H was constant, an increase in aspect ratio H⁄W accelerated atomic diffusion at void surfaces and bonding interfaces, facilitated void shrinking and increased the bonded area. This can improve the strength of diffusion bonded joints. The percent of bonded area can be predicted by numerical analysis for surfaces prepared by lathe machining.