Investigations on the Structure, Mechanical Property, Wear and Oxidation Resistances of TiAlSiN Coatings by Tailoring Al/(Al + Ti) Ratios

Abstract

Previous studies have broadly dealt with TiAlSiN coatings that exhibit promising characteristics as surface protective layers for antiwear and antioxidation applications. In this regard, revealing the correlations among coating composition, structure, and properties is vitally important for developing advanced TiAlSiN coatings. The present work addresses the issue by studying the structure and properties of TiAlSiN coatings by tailoring Al/(Al + Ti) ratios. To this end, TiAlSiN coatings are produced by arc deposition with the Al/(Al + Ti) ratios of 0.31, 0.42, 0.51, and 0.62, respectively. The results show that, when the Al/(Al + Ti) ratio ranges from 0.31 to 0.51, the phase structure is mainly TiN phase, and the hardness, wear resistance and oxidation resistance of the films are increased with the rise in the Al/(Al + Ti) ratio. When the Al/(Al + Ti) ratio reaches 0.62, the oxidation resistance of the coating does not improve significantly, while the mechanical and wear properties of the coating are deceased due to the formation of w‐AlN phase. Therefore, the appropriate Al/(Al + Ti) ratio at 0.51 provides overall improvements including mechanical properties, and wear and oxidation resistances under operation conditions. These findings show that optimizing the Al/(Al + Ti) ratio is a promising way to develop TiAlSiN coatings with advanced structure and properties.