Reactive infiltration synthesis of TiB2-TiC particulates reinforced steel matrix composites

The reactive infiltration synthesis of steel matrix composite reinforced with in situ TiB2-TiC particulates by the self-propagating high-temperature synthesis (SHS) reaction of the Ni-Ti-B4C system during casting was investigated. The as-cast microstructures of the in situ processed composites reveal a uniform distribution of TiB2-TiC particulates with a fine size of ∼5.0 μm. Although, microstructural characterization shows the absence of macro-pores and blowholes, the Ni content in the system has a significant effect on the presence of micro-porosity in the composites. Moreover, the results show that the densities of the composites are lower than those of medium carbon steel and high-speed (HS) steel. Although, the hardness values of the composites are significantly higher than that of medium steel and lower than that of HS steel, the wear resistance values of the composites are higher than those of medium steel and HS steel.