Deposition and characterization of TiAlSiN coatings prepared by hybrid PVD coating system

Abstract

TiAlSiN coatings with different Si contents were deposited on silicon and high-temperature alloy by using a hybrid physical vapor deposition coating system, where the cathodic arc ion plating was combined with a twin target mid-frequency magnetron sputtering. The chemical composition, microstructure, cross-sectional structure and morphology were carried out by X-ray photoelectron spectroscope (XPS), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and transmission electron microscope (TEM), respectively. NanoTest 600 nanomechanical system and ball-on-disc friction tester were used to investigate the mechanical and friction properties of TiAlSiN coatings. The worn surface of the TiAlSiN coatings and counterballs were investigated by means of surface profilometer and optical microscope. The wear rates were also measured by surface profilometer. The results showed that the Si addition did not change the coatings growth orientation, and the coating transfered into amorphous phase when the Si content reached about 13.9 at.%. The tribological properties and the hardness were improved by solid solution of Si atoms and grain boundary strengthening of SiNx amorphous phase with moderate Si content addition. In addition, the SiNx amorphous phase improved oxidation resistance of TiAlN coating, but with a high Si content (more than 8.3 at.% in this work) the agglomeration of SiNx amorphous phase would reduce the mechanical properties and oxidation resistance of the coating. Copyright © 2014 John Wiley & Sons, Ltd.