Structure and properties of (AlCrMnMoNiZrB0.1)Nx coatings prepared by reactive DC sputtering

The microstructure and properties of AlCrMnMoNiZrB_0.1 nitride films prepared by reactive direct current sputtering at various N₂-to-Ar flow ratios (R_N) were investigated. The films had an amorphous structure at low R_N and a face-centered cubic structure at a high R_N. As the R_N increased, the decrease in clusters and defects resulted in a dense columnar structure and low surface roughness. The peak hardness and modulus of the nitride films were 10.3 and 180 GPa, respectively. The enhanced hardness is ascribed to the increased metal-nitrogen bonding, solid solution strengthening of several metallic nitrides, and lattice strain. The nitride films deposited at R_N = 0.2, 0.5, and 0.8 had friction coefficients of 0.16, 0.12 and 0.15, respectively. Wear-out failure occurred within 400 s when R_N = 0 and 1.0. Adhesive wear was the dominant wear mechanism.