Microstructure of MC-Fe Composite Layer on Carbon Steel by Laser Surface Alloying

Laser alloying using carbide forming elements (Ti, Nb, and V) was carried out to form an MC-Fe composite coating on a carbon steel substrate for improving wear resistance. The microstructure of laser alloyed zone was studied by OM, SEM/EDS, STEM, and XRD to reveal the effect of additional elements and laser alloying conditions on the distribution of carbides. The laser alloyed zone was found to consist of MC carbide and iron matrix. Hardness and wear properties of the laser alloyed zone were improved as compared with the laser transformation hardened sample. Dispersion of carbide within the laser alloyed zone is shown to be effective in decreasing the friction coefficient and improving wear resistance.