Comparison of Al-Si-N nanocomposite coatings deposited by HIPIMS and DC magnetron sputtering

In agreement with previous studies, the coatings had a high transparency in the visual and near IR range; an optical band gap (E04) between 4.6 and 5.2 eV and a refractive index between 1.9 and 2.1 was observed. The ternary coatings studied here were found to be hard with the HIPIMS coatings (combined average 22 ± 3 GPa) being harder than their DCMS counterpart (combined average 17 ± 1 GPa). A maximum hardness of 27 GPa was observed for the sample deposited with HIPIMS and a Si-content of 7 at.%.