Jiang Longtao

Effect of Graphite Particle Reinforcement on Dry Sliding Wear of SiC/Gr/Al Composites

Abstract The 40%SiC/5%Gr/Al composites with various-sizes graphite addition were fabricated by squeeze casting technology, and their friction and wear properties were investigated. Results showed that after the addition of graphite the friction coefficient of composites decreased and the wear resistance increased by 170 to 340 times. In addition, wear resistance was improved with increasing of graphite particle size, which is attributed to the enhancement of integrity of lubrication tribo-layer composed of a complex mixture of iron oxides, graphite as well as fractured SiC particles and some fine particles containing aluminum.

Microstructure Evolution of Ti-Al-C System Composite

Abstract Ti-Al-C composite was fabricated by infiltration-in situ reaction . The as-cast material was prepared by pressing molten pure aluminum into the preform composed of titanium particles and carbon fibers. In situ reacted samples were obtained by heating the as-cast material from 600 to 1000 °C, and holding for 1 h at different temperatures. The morphology and elemental composition of samples were analyzed by scanning electron microscope and Energy dispersive X-ray, respectively. In addition, the phase composition of products was inspected by X-ray diffraction. Results show that TiAl 3 and Al 4 C 3 are formed at low temperature; with increasing of temperature, TiAl 3 decomposes and TiC precipitates; at high temperature, the oxidation occurs resulting in the formation of Al 2 O 3 . The mechanism of Ti-Al-C system composite during in situ reaction procedure is as following: formation-decomposition-precipitation-oxidation.