47th International Conference on Metallurgical Coatings and Thin Films-ICMCTF, California, United States Of America, 26 - 30 April 2021
Ternary and quaternary hard coatings based on carbonitrides of transition metals with amorphous matrix have many advantages; these have high hardness, adhesion, abrasion, oxidation, and corrosion resistance. Functional properties can be gained by adding definite amounts of different transition elements to carbonitride-based coatings. In this study, mechanical and tribological properties were investigated by adding Nb and Zr transition elements to TiBCN based coatings. The coatings were deposited on 4140 tool steel and the silicon wafer. TiBCN-based coatings with high adhesion and dense microstructure were synthesized with CFUBMS (Pulsed-dc+HiPIMS) using Cr, Ti, TiB2, Nb, Zr targets and Ar, N2, C2H2 gases. Microstructural properties of the coatings were obtained from the coatings on the silicon wafer and 4140 steel using SEM, XRD, and XPS. The mechanical properties of coatings synthesized on 4140 steel base materials have been characterized by Microhardness and Scratch tests. The hardness and adhesions of TiBCN-based coatings, which were grown by adding Nb and Zr, respectively on Cr:CrN graded structure (~200nm) as the transition layer, were optimized depending on the process parameters. Scratch test results showed that the adhesion strength varied as a function of the Nb and Zr target negative bias voltages. The highest adhesion strength was obtained as Lc:80N at -800V with adding Zr. In the case of the Nb adding, the highest adhesion strength was obtained as Lc:57N. Adhesion and microhardness test results showed that the utilization of bias-voltage with HiPIMS to the targets and pulsed-dc to the base material was the most effective coating parameter in the critical load and the hardness properties. Friction coefficients were observed as the lowest value, µ≈0.163 in TiBCN-Nb coatings, while it was observed as µ≈0.337 in TiBCN-Zr coatings.