Effect of Temperature on the Tribological Properties of Hafnium Carbonitrides Coatings

Abstract

For industrial processes in which refractory metals are necessary, hafnium carbonitride exhibits excellent performance due to its high thermal conductivity and resistance to oxidation. In this study, hafnium carbonitride was deposited on Inconel 718 steel and silicon (100) substrates. The objective was to characterize the wear properties as a function of temperature. The layers were deposited by physical vapor deposition (PVD) in an R.F. sputtering magnetron system from carbon targets and high-purity hafnium (99.99%). The wear tests were carried out at temperatures of 100 °C, 200 °C, 400 °C, and 800 °C in non-lubricated conditions. The coefficient of friction (COF) was recorded in situ. The heat treatment temperature on coatings is essential in determining anti-wear efficiency. It was determined that high temperatures (800 °C) improve resistance to wear. High-resolution XPS spectra were used to detect the chemical states of Hf 4f5/2 and Hf 4f7/2. The 4f5/2 and 4f7/2 binding energy indicates the presence of HfN and HfC. Using the TEM technique in bright field mode allowed us to know the orientation, crystallographic structure and interplanar distances of the HfCN. The topography of the coatings, by AFM, shows uniform grains and very small characteristics that determine the low surface roughness value. The SEM image of the cross-section of the HfCN coating shows homogeneity of the layer; no cracks or deformations are observed.