Fabrication And Study On Properties Of TiC Particles Reinforced Aluminum Matrix Composites

The course of reaction of Ti-C- Al-Ni, microscopic morphology and performance of composites were studied by using DSC, X-ray, SEM etc. The influences of thermodynamics, ingredient, explosion temperature and other factors on the morphology of products were investigated, then found 70wt%(Ti-C)-Al-Ni and 80wt%(Ti-C)-Al-Ni systems are found to be suitable to fabricate TiC particles reinforced aluminum matrix composites by SHS casting technology. The mechanical property and wear resistance of the composites were also tested.The thermodynamic calculation shows that TiC and NiAl are the stablest phases products of Ti-C-Al-Ni system. The explosion reaction is composed of two procedures. Al+Ni-*NiAl and Ti+C→TiC , in which the latter reaction is provoked by the heat of former reaction, TiC and NiAl are the final products. The content of Ti-C has obvious influence on starting temperature and morphology of the products. With the increase of the content of Ti-C, starting temperature and adiabatic temperature of the reaction rise. Spherical NiAl melts completely or partly and TiC change markedly from small , spherical form to approximate sphericity. When the content of Ti-C is 50wt%, TiC/NiAl intermetallic composite can be obtained. When the content of Ti-C is 70～80wt%, TiC particles grow up with anomalous morphology and molten NiAl reduce greatly. TiC particles reinforced aluminum matrix composites were fabricated with 70wt%(Ti-C)-Al-Ni and 80wt%(Ti-C)-Al-Ni system. The microstructure of the composite is TiC particles distributed in the aluminum matrix with diameter of 2 μm.The results of properties evaluation of TiC particles reinforced aluminum matrix composites show that the hardness, tensile-strength and wear resistance are enhanced with the increase of the content of Ti-C. The tensile-strength of 3vol% and 3.5vol%TiC particles reinforced aluminum matrix composites is 180MPa and 230MPa, respectively, with 2.5 and 3 times higher hardness and 3.3 and 4.2 times higher wear resistance than aluminum substrate. Abrasiveness is dominant mechanism during the dry sliding wear of the composites with some adhesiveness and oxidation wear, Fe is also found on the worn surface, and increases with the enhancement of the content of TiC.