Al-Cr-Si-N coating: Substrate temperature effect on mechanical and scratch behaviour

The demand for advanced coating materials in high-temperature and wear-resistant applications has led to the exploration of multicomponent systems that offer superior mechanical properties. Among these, AlCrSiN has emerged as a promising candidate owing to its ability to blend the thermal stability and hardness of AlCrN aided by grain refinement along with the presence of amorphous phase as a result of silicon addition. In this study, SS 304 substrates were used to deposit AlCrSiN thin films through magnetron sputtering process. This work focuses on the structural, hardness, scratch, wear and adhesion properties of AlCrSiN thin films as a function of substrate temperature. The AlCrSiN coating deposited at 400°C exhibited a hardness of 23 GPa and an (H/E) ratio of 0.08, which is an apparent measure of good wear-resistance coating. The work of adhesion significantly increased from 18 to 150 Jm−2 as the substrate temperature was gradually boosted from 30 to 500°C. Coatings facricated at room temperature and 300°C displayed an amorphous structure, while those deposited at 400°C and 500°C developed CrN/AlN crystallites averaging 16 nm in size within the amorphous matrix. Furthermore, the coefficient of friction (COF) was maintained between 0.27 and 0.30. These findings underscore the potential of AlCrSiN coatings to enhance the wear resistance and mechanical performance of substrates in demanding industrial applications, with substrate temperature playing a key role in optimizing coating properties.