LAUSR

Abstract Change in the mechanical properties of (Ti,Zr)(C,N) coatings by laser carburization was investigated in terms of bonding state and valence electron concentration (VEC). The doped carbon was analyzed for the formation of amorphous carbon phase with ID/IG of 0.85 and sp2/sp3 ratio of 2.13. The formation of carbide phase (TiC and ZrC) was substituted for nitrogen. The ratios of TiC/TiN and ZrC/ZrN were verified to be 0.10 and 0.26 by the analysis of the bonding environment using photoelectron spectroscopy. VEC was calculated to be 8.85 due to the transformation from (Ti,Zr)N (VEC = 9) to (Ti,Zr)(C,N). The decreased VEC was correlated with the decrease of the metallic state and the increase of p-d hybridized bond in valence band. As the measured elastic modulus and hardness increased from 420.3 GPa and 32.4 GPa for VEC = 9 to 442.1 GPa and 37.6 GPa for VEC = 8.85 before and after carbon doping, the change in resistive properties against the elastic strain was identified due to the increase in hybridized bonds.