STUDY ON THE RELATIONSHIP BETWEEN VALENCE ELECTRON STRUCTURE AND COATING ORIENTED GROWTH

The coating oriented growth has attracted great attention because of its effect on coating properties. In this paper, the valence electron structures of TiN and Ni were calculated with the empirical electron theory (EET) in solid and molecules for investigating preferred orientation of nitride coatings containing Ni. The calculation results show that Ni(111), CrN(100) and TiN(100) are the maximum crystal-face electron density, respectively. In CrN (or TiN) coatings, if Ni does not form a single nickel phase, CrN(100) (or TiN(100)) preferred orientation appears easily due to its high crystal-face electron density. When Ni exists as a single phase, CrN(100)/Ni(111) (or TiN(100)/Ni(111)) with the minimum crystal-face electron density difference is the most likely to appear in the coatings. Furthermore, high crystal-face electron density difference usually implies fine grain microstructure. The calculation results are consistent with the experimental results.