Through-process modeling and experimental verification of titanium carbonitride coating prepared by moderate temperature chemical vapor deposition

Abstract

In this work, the impact of temperature, pressure and gas flow on the chemical compositions, phases and deposition rates of MTCVD (Moderate Temperature Chemical Vapor Deposition) Ti(C,N) coatings is investigated by integrating thermodynamic calculations and computational fluid dynamics (CFD) simulations with key experiments. The thermodynamic calculations predict that both the C and the N contents of the films increase with increasing temperature under constant mixed gases and pressure, with the former increasing faster than the latter. CFD simulations indicate that the coating deposition rate decreases with increasing distance to the source gas for the hard metal samples loaded on the same tray. Subsequently, MTCVD-Ti(C,N) coatings were deposited at three different temperatures to verify the predicted chemical compositions and deposition rates. The experimental investigations are in reasonable agreement with the theoretical predictions. The present work applies a well-established strategy to meet the requirements of a controlled and robust process for MTCVD-Ti(C,N) coating with industrial applications.