For heavy alloys, which are tungsten-based sintered alloys, a diffusion bonding technology has been developed to expand the range of shapes that can be fabricated. In this study, to determine the optimal conditions for diffusion bonding, we investigated the heat treatment and pressing conditions, such as the heat treatment temperature, atmosphere, void space on the bonding surface, and pressure to press the bonding surface.
Investigation of the void space on the bonding surface showed that bonding was possible when the unevenness of the bonding surface was only a few micrometers. We determined the thresholds for the flatness of the diffusion-bonded product based on these results. In diffusion bonding, it is necessary to select the best bonding conditions depending on product shape.

4.Development_of_Diffusion_Bonding_Technology_for_Heavy_Alloys.pdf