Preparation and properties of TiCp/Cr15 high chromium cast iron composites

TiC_p reinforced high chromium cast iron composites with full density have been fabricated by liquid phase sintering technology with water atomized Cr15 high chromium cast iron powders and TiC particles as raw materials. The effect of TiC content on the microstructure evolution, phase composition and mechanical properties was investigated systematically. The research results show that the composites consist of TiC, M₇C₃ type carbides, martensite and a small amount of austenite; With the increase of TiC_p addition, the metal matrix is gradually partitioned into island-like fragments, and M₇C₃ type carbides are principally precipitated in them. Hence continuous TiC particle network is formed step by step either. The composites’ hardness steadily increases at the same time, while both its bending strength and impact toughness decline. The sintered composite obtains its optimized mechanical quality as the TiC_p addition amount is 20wt%, that is hardness of HRC 66.8, the impact toughness of 6.86 J/cm² and bending strength of 1343.10 MPa. Its hardness reaches the maximum value of HRC 67.20 while 25wt% TiC_p is added.