Tuning of structure, grain orientation and mechanical properties in reactively sputtered (Al,Mo,Ta,V,W)N

(Al,Mo,Ta,V,W)-N_0.79, -N_0.33, and -N_0.88O_0.12 coatings were sputtered in N₂-rich, N₂-lean, and N₂+O₂ containing atmospheres. The face-centered cubic structured coatings feature as-deposited hardness values of 32.3, 39.7, and 34.5 GPa, respectively. The (Al,Mo,Ta,V,W) N_0.79 and (Al,Mo,Ta,V,W)N_0.33 consist of highly oriented columns, plus some very large grains in the latter coating. During vacuum annealing at 800 °C for 30 h, the (Al,Mo,Ta,V,W)N_0.79 loses N down to 25 at.%, while the (Al,Mo,Ta,V,W)N_0.33 remains stable. Their alignment in chemical composition also caused an approach of their hardness values with 35.2 and 38.1 GPa, respectively. The (Al,Mo,Ta,V,W)N_0.88O_0.12 exhibits partly tilted and randomly oriented smaller columnar grains than the nitrides, and the hardness drops from 34.5 to only 14.1GPa when vacuum annealed due to massive phase-transformations toward individual oxides and the connected crack formation.