Study on the growth and wear characters of CVD coating deposited on Ti(C, N)-based cermets with adding different C/N ratios of Ti(C, N) powders

This paper assessed the growth of CVD composite coatings on three kinds of cermets and the subsequent high-temperature frictional properties. The carbon to nitrogen ratios (C: N) of Ti(C1-x, Nx) powders added to these three cermets were 5:5,7:3 and 10:0, respectively. It was prepared by powder metallurgy. The TiN/α-Al2O3/Ti(C, N)/TiN multilayer coatings were deposited on different Ti(C, N)-based cermets. The results showed that the crystallinity of the composite coating was affected by the contents of nitrogen content. The inner layer TiN coating exhibited a nano-columnar crystal structure, which detected (111) and (200) orientation texture by XRD. The α-Al2O3 coating and Ti(C, N) coating of the three specimens were coarse columnar crystal structures. The variation in the nitrogen content led to the different performances of the coating. Meanwhile, The CVD coating with a C/N ratio of 7:3 had the best comprehensive properties, because the substrate had similar grain-forming directions and more shape nucleation points. The Electron Backscattered Diffraction (EDSB)、Scanning Electron Microscope (SEM) and Energy Dispersive Spectrometer (EDS) were used to further analyze the microstructure of the samples. The Coating Al2O3 displayed excellent mud (100) value, which indicated that the preferred texture (100) existed and improved the performance of the Al2O3 coating. The adhesion strength of the composite coating on Ti(C0.7, N0.3)-based cermets is the highest. The high-temperature friction wear of the coating was further investigated. Group Y2, which expressed the sample of Ti(C0.7, N0.3)-based cermets CVD coating, demonstrated the lowest wear rate. All control groups’ wear mechanisms included abrasive wear, diffusion wear, and oxidation wear.