A molecular dynamics simulation of Ti–TiN multilayer deposition on FeCrNi(001) alloy substrate

Abstract In this work, to investigate the physical vapor deposition (PVD)-deposited Ti–TiN multilayer coating on the FeCrNi (Fe 78.4%- Cr 15.17%- Ni 6.43%) substrate, made of GTD 450 compressor blade material, the process was simulated using molecular dynamics (MD) method with the 2NN-MEAM (nearest-neighbor modified embedded-atom-method) potential. The results revealed that although the Ti film growth mode is epitaxy, the N adatoms diffusion on the Ti surface prevents the epitaxial growth of the TiN film. Comparing the film's structure showed that the surface morphology and crystallinity of Ti are better than those of TiN. The average mean biaxial stress is compressive in both the substrate and deposited layers, while it becomes tensile in the substrate-Ti interface layers. On the other hand, in spite of being compressive the average normal stress of the substrate, the deposited layers are tensile. Increasing the film's thickness increases the average mean biaxial stress of the substrate-Ti interface and the Ti–TiN film. The results showed that the enhancement of substrate temperature from 600 to 800 K causes to reduce the average mean biaxial stress of the substrate, the substrate-Ti interface, and the TiN film surface. However, growing the number of layers with a constant film thickness reduces stresses in the substrate, the interface, and the film region. Enhancing incident energy increases the average mean biaxial stress of both substrate and film. In contrast, it decreases the surface roughness of the film.