On the phase formation of cathodic arc evaporated Al1−xCrx-based intermetallic coatings and substoichiometric oxides

The dense columnar structure of the intermetallic coatings (hardness values between 2.5 and 10.2 GPa) turns into a nano-composite-like morphology for depositions with 50 and 100 sccm O2 p.a.s., which in turn leads to a significant hardness increase up to ~24 GPa. Among all coatings investigated, the Cr-rich compositions have higher hardness and denser morphology than the Al-rich layers.