Synthesis and Characterization of Microwave and Conventional Combustion Synthesized Alumina-Titanium Carbide Powders

Al2O3-TiC powders were produced from microwave and conventional-combustion synthesized mixtures of TiO2, C and Al. Different types of precursors such as rutile and anatase TiO2, as well as carbon black, graphite and activated carbon powders were used. The different types of precursors and heating methods affected the combustion behavior. Combustion using microwaves could be achieved in less than 3 min, which was 10 times faster than conventional combustion. The composition of rutile-carbon black-aluminum gave the shortest ignition time using microwave energy, whereas the mixture containing activated carbon ignited fastest using conventional heating. Nevertheless, in both cases samples with anatase required longer time to ignite and thus gave higher combustion temperatures than ones with rutile. An incomplete combustion product observed when activated carbon was the carbon source. The synthesized powder was fragmented and angular in shape with the largest agglomerate size limited to smaller than 25 microns.