Mechanical Properties and Thermal Stability of CrSiN/AlN Multilayer Coatings Using a Closed-Field Unbalanced Magnetron Sputtering System

Abstract

In this work, for high-temperature applications, CrSiN/AlN multilayer coatings with various bilayer thicknesses (A) were synthesized using closed-field unbalanced magnetron sputtering (CFUBMS) and their chemical compositions, crystalline structures and mechanical properties were investigated with glow discharge optical emission spectroscopy (GDOES), X-ray diffractometry (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and micro-hardness tester. Also, the thermal stability of the CrSiN/AlN multilayer coatings was evaluated by annealing the thin films at temperatures between 600 degrees C and 1000 degrees C for 30 min in air. The hardness of the CrSiN/AlN multilayer coatings was measured to be in a range from approximately 23 to 35 GPa. A maximum hardness and elastic modulus of approximately 35 and 259 GPa, respectively, were obtained from the coating with Lambda = 1.9 nm. However, the thermal stability of the CrSiN/AlN multilayer coating with Lambda = 3.0 nm was better than that of coating with Lambda = 1.9 nm and the relatively high hardness of 24 GPa was maintained even after annealing at 1000 degrees C.