Structure and hardness of vacuum arc deposited multi-component nitride coatings of Ti, Zr and Nb

Ternary transition-metal nitride coatings of(Ti,Zr)N, (Ti,Nb)N and (Zr,Nb)N were deposited using a triple cathode vacuum are deposition system by simu ltaneously operating two cathodes of the appropriate metals in a low-pressu re nitrogen background. The magnetically collimated plasma flux distributio n was measured using a 13-element ion saturation current probe. The microst ructure, composition, and hardness of the coatings were determined using X- ray diffraction, Auger electron spectroscopy, and Vickers indentation, resp ectively. The plasma flux distribution had two peaks whose relative positions were re lated to the two cathodes. Coatings applied to extended substrates had a co mpositional gradient. In almost all cases, the ternary nitrides had a singl e-phase solid-solution microstructure, whose lattice constants had values i ntermediate between those of the parent binary nitrides. The ternary coatin gs were considerably harder than either of the parent binary nitrides. (Ti, Nb)N had the highest microhardness: similar to 50 GPa. (C) 2000 Elsevier Sc ience S.A. All rights reserved.