Microstructure and performances of MoN/CrMoN bi-layer coatings

This study utilized direct current (DC) magnetron sputtering to produce a MoN/CrMoN bi-layer film. The impact of the MoN buffer layer thickness, varying Mo DC power, and substrate plasma etching pre-treatment on the structural and mechanical properties of MoN/CrMoN bi-layer films was investigated. With fixed CrMoN film deposition parameters an increase in the thickness of the MoN buffer layer led to a reduction in the grain size of the MoN/CrMoN bi-layer film and an enhancement in the surface hardness of the film coating. Fixed MoN buffer, Cr DC power and change the Mo DC power, the results show that as the Mo power increases, the crystal position of the (111) crystal plane diffraction peak of the MoN/CrMoN bi-layer film shifted to a higher angle along with changes in internal stress. Substrates pre-treated by plasma etching showed increased surface roughness, hydrophilic tendency, and good film coating adhesion. By increasing the plasma etching power of the substrate pre-treated, the MoN/ZrMoN bi-layer film has better mechanical properties. The H, E, H/E ratio H³/E² ratio, Re, and the coefficient of friction of the MoN/CrMoN bi-layer films are 14.59 GPa, 144.8 GPa, 0.101, 0.148, 65.2%, and 0.39, respectively.