Synthesis and characterisation of TiC reinforced CoCrFeNi composite by hot-pressing sintering

Ti, Co, Cr, Fe, Ni and graphite powders were used to fabricate TiC reinforced CoCrFeNi composite by mechanical alloying and consequently hot pressing sintering at 1200 degrees C for 1 h. Results indicated that Co, Cr, Fe and Ni powders were deformed, cold welded and crushed repeatedly during milling and an face-centred cubic-structured solid solution was obtained after milled for more than 10 h. Nano-sized TiC and micron-sized Cr7C3 type carbides were formed and embedded in the CoCrFeNi matrix dispersedly after sintering. The hardness and compressive fracture strength of the sintered composite reached 501 HV and 2.55 GPa, respectively, which could be ascribed to the presence of large amount of in-situ formed TiC and Cr7C3 type carbides in the composite.