Effects of Processing Parameters on the Fabrication of in-situ Al/TiC Composites by Thermally Activated Combustion Reaction Process in an Aluminium Melt using Al-TiO2-C Powder Mixtures

A feasible way to fabricate in-situ Al/TiC composites was investigated. An elemental mixture of Al-TiO2-C pellet was directly added into an Al melt at 800-920 degrees C to form TiC by self-combustion reaction. The addition of CuO initiates the self-combustion reaction to form TiC in 1-2 mu m at the melt temperature above 850 degrees C. Besides the CuO addition, a diluent element of excess Al plays a significant role in the TiC formation by forming a precursor phase, Al3Ti. Processing parameters such as CuO content, the amount of excess Al and the melt temperature, have affected the combustion reaction and formation of TiC, and their influences on the microstructures of in-situ Al/TiC composites are examined.