Structure and mechanical properties of multi-element (AlCrMnMoNiZr)Nx coatings by reactive magnetron sputtering

The paper investigates the structure and properties of AlCrMnMoNiZr nitride films prepared by reactive direct current sputtering at various N2-to-Ar flow ratios (RN). The films deposited at low RN show amorphous phase, micro-voids and clusters structure, and hence have low hardness and modulus. As RN increases, the films present face-centered cubic structure (FCC) with (1 1 1) preferred orientation, small crystalline sizes, dense structure, smooth surface, and consequently have higher hardness and modulus. When RN = 1.0, the nitride film has peak hardness and modulus of 11.9 GPa and 202 GPa, and the highest value of H/E and H3/E2. Compared with the metallic film its tribological properties are relatively worse. This can be ascribed to the difference in film thickness. According to the observations of the typical surface morphologies, the dominant wear mechanism of the AlCrMnMoNiZr nitride films is adhesive wear.

► RN is N2-to-Ar flow ratios, which effect on the structure and properties of films.
► Amorphous and FCC structures can be achieved at low RN and high RN, respectively.
► Solid solution strengthening and lattice strain enhanced the hardness of the films.
► High friction coefficient of the nitride films deposited at high RN can be ascribed to the difference in film thickness.
► Adhesive wear is the dominant wear mechanism in the films.