IN SITU SYNTHESIS OF TiC–TiB2 REINFORCED FeCrSiB COMPOSITE COATING BY LASER CLADDING

TiC and TiB2 reinforced iron based metal matrix composite (MMC) coating was synthesized on mild carbon steel by laser cladding employing B4C, ferrotitanium, and FeCrSiB mixed powders. The microstructure and chemical composition were analyzed by means of SEM, EPMA, and XRD. Results show that the coating mainly consists of α–Fe(Ni), TiB2, TiC, B6Fe23, Cr2B, and M23C6. TiB2, and TiC reinforcements are formed in situ through the reaction between B4C and ferrotitanium. Hardness and wear measurement results show that the hardness and wear resistance of the composites are much higher than that of the as-received sample.