High Temperature Oxidation Behaviors of CrNx and Cr-Si-N Thin Films at 1000 °C

Abstract

The high temperature oxidation performance of nitride thin films has become an important issue when they are used as protective coatings on dry cutting tools or on die casting molds. In this study, the high temperature oxidation behaviors of CrNx and Cr-Si-N thin films were investigated at 1000 °C for 6 h in ambient air. The CrNx and Cr-Si-N thin films were prepared by a bipolar asymmetric pulsed direct-current (DC) magnetron sputtering system. Cr-Si-N films with silicon content ranging from 3.9 to 12.2 at.% were deposited by adjusting the Si target power. A thermogravimeter was adopted to study the oxidation kinetics of thin films. The weight gains were measured to calculate the parabolic rate constants of thin films. X-ray diffraction, X-ray mapping, and Auger electron spectroscopy were employed to study the microstructure and elemental redistributions of oxidized thin films. The as-deposited CrNx and Cr-Si-N thin films consisted of CrN and Cr2N mixed phases. The faceted Cr2O3 surface oxides, porous inner oxide layer, and oxygen-containing CrSi2 phases were found for the CrN film after oxidation test. On the other hand, the Cr-Si-N film containing 12.2 at.% Si showed a dense surface oxide layer and a thick and compact nitride layer, which indicates its best oxidation resistance. The high temperature oxidation resistance of Cr-Si-N thin films was improved by increasing Si content, due to the amorphous matrix contained nanocomposite microstructure and the formation of amorphous silicon oxide to retard the diffusion paths of oxygen, chromium, silicon, and nitrogen. The lowest parabolic rate constant of 1.48 × 10–2 mg2/cm4/h was obtained for the 12.2 at.% Si contained Cr-Si-N thin films, which provided the best oxidation resistance at 1000 °C for 6 h in this work. It should be noted that the residual tensile stress of thin film had a detrimental effect on the adhesion property during the oxidation test.

Effects of Bias Voltages on the Structural, Mechanical and Oxidation Resistance Properties of Cr–Si–N Nanocomposite Coatings

“…Therefore, the high temperature oxidation resistance property of the Cr-Si-N coatings prepared under this parameter is studied. From the XRD spectra shown in Figure 9, it can be seen that there are only diffraction peaks of CrN in the as-deposited Cr-Si-N coatings [26].…”

Crystal Structure Prediction of the Novel Cr2SiN4 Compound via Global Optimization, Data Mining, and the PCAE Method

“…Four kinds of Cr-Si-N coatings are known that are considered to be harder than the CrN coating [28]. Nanocomposite Cr-Si-N thin films (usually in the form of nanocolumns or nanoclusters of CrN embedded in an amorphous Si 3 N 4 matrix) also have higher hardness and oxidation resistance compared with CrN thin films [5,6,[15][16][17][18]29]-their hardness can be increased by up to ~9 GPa [2,3,30,31], while their oxidation resistance is significantly improved at temperatures well above the oxidation limit of ~600-700 • C of CrN [6,32,33].…”

The effect of duty cycle on the mechanical and electrochemical corrosion properties of multilayer CrN/CrAlN coatings produced by cathodic arc evaporation

“…As reported by researchers, CrN compounds are known to be better than TiN in mechanical, tribological, oxidation and corrosion behaviours [8,9]. The use of ternary metal nitrides and multilayer systems such as CrAlN, TiAlN, Ti/TiN, TiAlSiN, TiAlSiN/CrN, and AlCrN/TiAlSiN has developed on a particularly large scale in the recent years, due to their excellent tribological performance, proper mechanical properties, good stability at high temperature, and suitable high-temperature oxidation and corrosion resistance, in comparison with the aluminium-free coatings such as TiN and CrN [10][11][12].…”