Transient liquid phase bonding of TiC reinforced magnesium metal matrix composites (TiCP/AZ91D) using aluminum interlayer

The composition, microstructure and mechanical properties of transient liquid phase (TLP) bonded TiC reinforced magnesium metal matrix composite (TiCP/AZ91D) joints using aluminum interlayer depend on both bonding time and bonding temperature. With the increase of the bonding time at the bonding temperature of 460 °C, the concentration of Al in the joint centerline decreased and the joint microstructure changed from α-Mg solid solution, AlMg and Al12Mg17 compounds to α-Mg, Al12Mg17 and TiC particulates. At the bonding temperature of 480 °C, the microstructure of joints consisted of α-Mg, Al12Mg17 and TiC particulates, and TiC particulates aggregated along the bond line when the bonding time was 60 min. The increased amount of Al12Mg17 compound and aggregation of TiC particulates were the main reason for affecting the mechanical properties of joints. The joint shear strength of above 58 MPa can be obtained at the bonding temperature of 460 °C or 480 °C for the bonding time of 20 min.