SOLIDIFICATION PROCESSING AND TRIBOLOGICAL BEHAVIOR OF PARTICULATE TIC-FERROUS MATRIX COMPOSITES

Particulate TiC-reinforced ferrous matrix composites were processed by solidification of (1) an FeTiC melt of appropriate composition from which particulate titanium carbide precipitates and (2) an FeC melt in which particulate titanium carbide is dispersed through electromagnetic stirring. The microstructure of composites processed by precipitating titanium carbide was controlled by controlling melt composition and homogeneity, as well as cooling rate. That of composites processed by dispersing titanium carbide powder in a steel or cast iron melt was controlled by controlling the original melt composition, volume fraction and particle size of titanium carbide added, mixing temperature and time, and cooling rate. The specific wear rate and the friction coefficient between a diamond stylus and the polished surface of composite specimens decreased with increasing volume fraction of titanium carbide and decreasing carbide particle size and spacing. They also decreased with increasing steel matrix microhardness, achieved through heat treatment and martensitic transformation. © 1990.