Fabrication of titanium carbide-reinforced iron matrix composites using electropulsing-assisted flash sintering

Abstract

As a potential substitute for tungsten carbide-cobalt, titanium carbide-reinforced iron matrix composites with different titanium carbide content were fabricated using flash sintering. The as received mixed titanium carbide and steel powders were directly loaded into a mold and sintered for 10 s. Few voids were visible in the sintered samples using optical and scanning electron microscopes, which suggested that the samples were completely dense. As the titanium carbide content increased, the hardness of the samples linearly increased from 700 HV to 1350 HV. However, the addition of titanium carbide particles reduced the compressive strength of the samples from 3.5 GPa (5 wt% titanium carbide) to 1.5 GPa (50 wt% titanium carbide). The increasing porosity at the phase boundary and decreased free path of the binder network caused the strength of the sintered samples to decrease. The excellent bond strength at the interface between titanium carbide and the high-speed steel matrix is an indication for the excellent application potential of this cemented carbide. In addition, the electropulsing-assisted flash sintering method described in this paper should be feasible for all other conductive composites and could provide a pathway for the ultrafast fabrication of ceramic-reinforced metal composites.