Microstructure and mechanical properties of diffusion bonded Al/Mg2Si metal matrix in situ composite

In this research, Al/Mg2Si composite produced by gravity casting, was joined by diffusion welding technique at 6 MPa pressure with various welding temperatures and durations. This metal matrix composite (MMC) containing 15% Mg2Si particles was produced by in situ technique. Specific diffusion bonding process was introduced as a low vacuum technique. Microstructure and shear strength of the joined areas were determined. Scanning electron microscopy examination was carried out on the welded interfaces and shear tests were conducted to the samples interface to find out the effect of welding temperatures and durations on the weldability. It was found that high welding temperatures resulted in increase of shear strength. However, increase in welding duration did not make any detectable changes. The bonded interface could be developed as a wavy state depending on the amount of parent material deformation that was associated with bonding temperature. Results indicated that MMC can be joined by diffusion welding technique successfully with satisfactory shear strength.