Effects of Zr, Nb, or Si addition on the microstructural, mechanical, and corrosion resistance of TiCN hard coatings

Stoichiometric TiZrCN, TiNbCN, and TiSiCN coatings, with Zr, Nb, or Si as alloying elements, were deposited on Si and M2 high speed steel substrates by the cathodic arc technique in a mixture of N₂ and CH₄ gases. Coatings with a C/N ratio value of about 0.5 have been prepared and comparatively investigated for elemental and phase composition, texture, adhesion, and anticorrosive properties. All coatings consisted of fcc solid solutions, with an (111) preferred orientation. The addition of either Zr, Nb, or Si in the basic structure of TiCN coatings resulted in adhesion enhancement (critical loads in the range 20–30 N) and increased corrosion resistance, as tested in 3.5% NaCl solution.