Investigation on microstructure and mechanical properties of diffusion bonded Al/Mg2Si metal matrix composite using copper interlayer

Diffusion bonding of Al/Mg₂Si metal matrix composite (MMC) using Cu interlayer at optimal bonding temperature of 540 °C for various bonding durations was investigated. 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. The composition and microstructure of the joined areas were examined by X-ray diffraction (XRD) and scanning electron microscopy equipped with energy dispersive X-ray spectroscopy (EDS). Microhardness and shear tests were conducted to the samples to evaluate the effect of bonding duration on weldability. Several different diffusion layers exist at the bond region depending on the bonding duration. The shear strength of joints increased with bonding duration due to elimination of CuAl₂ brittle diffusion layer.