Mixed Al-Ag-Cu and Al-Ag-Cu-Ti powders were used as interlayers for transient liquid phase diffusion bonding (TLP bonding) of SiC particulate reinforced 2618 aluminum alloy matrix composite (SiCp/2618Al MMC). The results show that by using mixed Al-Ag-Cu powder with the eutectic composition as an interlayer, SiCp/2618Al MMC can be TLP bonded at 540 degrees C, however, the joining layer is porous. Adding a certain amount of titanium into the Al-Ag-Cu interlayer, the TLP bonding quality can be improved. The titanium added into the Al-Ag-Cu interlayer has an effect of shortening the solidification time of the joining layer, thus decreasing SiC particles from the parent materials entering into the joining layer. The joints bonded using Al-Ag-Cu-Ti interlayers have a maximum shear strength of 101 MPa when 2.1% titanium is added.