Surface evaluation of carbonitride coating materials at high temperature: an investigation of oxygen adsorption on crystal surfaces by molecular dynamics simulation

In the presented work, changes in the surface morphology and crystal structure of the coatings obtained by adding Zr, Si, Nb, ZrSi and ZrNb elements added to the TiCN base matrix after thermal annealing at high temperature were studied. The novelty of the current study lies in the comprehensive investigation of the structural and compositional changes of carbonitride coatings, their behavior under thermal conditions, and the implications for their practical applications. The goal of the proposed experiment was to evaluate the influence of composition and structure on the oxygen adsorption tendencies at both high (2000 –1500 K) and low temperatures (0–100 K), through molecular dynamics. The formation mechanism of the gas and oxide phase on the surface of the coatings during the thermal annealing was simulated by the molecular dynamics code. The formation of gas products before the formation of the oxide layer on the surface of the coatings was shown by molecular dynamics simulation. Based on the structural analysis conducted by scattering X-rays from small angles, it was determined that a new phase is formed on the surface of the coatings. Formation of free cubic TiC phase was observed in both TiZrSiCN and TiZrNbCN coatings under the influence of temperature. Degradation of surface morphology and formation of pinholes were found after thermal annealing. The experimental formation of the oxide phase on the surface of the sample up to a temperature of 1270 K expands the application possibilities of the coatings in various industrial fields including catalysis.