Diffusion Welding of Al-α-Si3N4 Composite Materials

In this study, Al-alpha-Si(3)N(4 )composite, produced by powder metallurgy method, were joined at 2.5 MPa pressure with various welding temperatures (620, 630, and 640 degrees C) and durations (1,1.5, and 2 h.) by diffusion welding method. Optical microscopy examination was carried out from welded interfaces and shear tests were also conducted to the sample interfaces to find out the effect of welding parameters and amount of alpha-Si3N4 reinforcement on the weldability properties of composite materials. The test results show that increase in the welding temperature and duration resulted in increase shear resistance of the welded zone. Results indicated that optimum parameters (welding temperatures, durations and amount of alpha-Si3N4 are 640 degrees C, 2 h., and 15wt % respectively) MMCs produced in this study could be joined by diffusion welding technique successfully with the 97.5 % strength of base material.