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. TiZrCN, TiNbCN, and TiSiCN coatings were prepared by the cathodic arc technique in a mixture of N2 and CH4 gases. TiNbCN coating showed the highest resistance to corrosion attack in 3.5% NaCl, due to its high adhesion to the steel substrate and to the lowest roughness. Ti‐based carbonitride coatings with alloying elements are suitable coatings to reduce the corrosion processes of M2 HSS in NaCl aggressive environment.