Microstructure and mechanical properties of TiC particle enhanced high chromium iron

TiC particle (TiC_P) reinforced-sintered high chromium cast iron (HCCI) composites containing 20% Cr by mass were prepared by powder metallurgy (PM) and super solid phase line liquid phase sintering (SLPS). The effect of TiC particle content (mass fraction) on the phase composition, microstructure, and mechanical properties of the TiC_P/HCCI composites was systematically studied by means of optical microscope, scanning electron microscope (SEM), and X-ray diffraction (XRD). The subsequent heat treatment research was also carried out. The results show that, the relative density of the TiC_P/HCCI composites prepared by SLPS is above 97%, and the phase composition is composed of martensite, austenite, M₇C₃ carbide, and TiC. The TiC particles mainly distribute along the interface between the metal matrix and carbide in HCCI. With the increase of TiC content, the hardness of the composites increases to HRC 67.2, while the impact toughness decreases gradually. The fracture mechanism of the composites changes from the quasi cleavage fracture to the inter-granular cleavage fracture. After the quenched treatment, the hardness of the TiC_P/HCCI composites can be further increased to HRC 69.3, which are expected to be the excellent wear-resistant materials with the hardness between HCCI and cemented carbide.