Investigation on Microstructure of Transient Liquid Phase Diffusion Bonded Joints of Al/Mg2Si Metal Matrix Composite

The growing demand for more fuel-efficient vehicles to reduce energy consumption and air pollution is a challenge for the automotive industry. Recently, Al-Mg2Si metal matrix composites (MMCs) have been developed for high-performance applications in automotive industries. Al- and Mg-based composites, reinforced with particulates of Mg2Si have been recently introduced as a new group of particulate metal matrix composites that are good candidates to replace Al–Si alloys used in aerospace and engine applications. Suitable joining technologies will be required if the materials are to be used as structural components. As-cast Al/Mg2Si metal matrix composite was joined by transient liquid phase diffusion bonding using Cu interlayer at various bonding temperatures and durations. This metal matrix composite containing 15 wt% Mg2Si was produced through in situ technique by gravity casting. Specific diffusion bonding process was applied as a low vacuum technique. The microstructure of joints was examined by scanning electron microscope equipped with energy dispersive X-ray spectroscopy and optical microscope. The microstructure of joints consisted of Al-α, CuAl2 and Mg2Si or Al-α and Mg2Si depending on bonding temperature and duration. Also, bonding temperature and duration affected aggregation zone of Mg2Si particles at bonded interface.

Keywords:

Al/Mg2Si metal matrix composite , Transient liquid phase diffusion bonding , Microstructure , Cu interlayer