Oxidation resistance of SiAlCN: H-coatings

Silicon–aluminum–carbon-nitride films were deposited by means of reactive RF magnetron sputtering onto various metal substrates. The films were prepared by sputtering a partially aluminum covered silicon target in a reactive gas mixture of nitrogen and acetylene. The composition throughout the depth of the films was investigated by glow discharge optical emission spectrometry (GDOES). Additionally mechanical properties (hardness, elastic modulus, and film thickness) were measured. The mechanical properties of the SiAlCN coatings were comparable to the properties of SiCN coatings. The coated samples were subjected to oxidation tests in air, at temperatures of 700–1000 °C. GDOES concentration–depth profiles of the samples were recorded before and after the oxidation test to study changes in the composition and the film–substrate interface. To determine the influence of the aluminum addition, the results are compared to SiCN coatings.