Nanocomposite Ti-Si-N, Zr-Si-N, Ti-Al-Si-N, Ti-Al-V-Si-N thin film coatings deposited by vacuum arc deposition

Thin films of Ti-Si-N, Zr-Si-N, Ti-Al-V-Si-N and Ti-Al-Si-N have been synthesized by reactively evaporating a metal or metal alloy cathode by a vacuum arc in a background of nitrogen gas and tetramethylsilane. The amount of silicon in the films was varied from 0 to 19 at.%. With increasing silicon content, the Ti-Si-N, Ti Al-V-Si-N and Zr-Si-N films were found to increase in hardness, the maximum recorded value being 42 GPa. The Ti-Al-Si-N films showed either a slight increase or decrease in hardness with silicon content. Structural studies showed that the increased hardness was accompanied by a reduction in the grain size, in the case of Ti-Al-V-Si-N, from 24 to 7.7 mn. Transmission electron microscopy (TEM) studies confirmed the X-ray diffraction (XRD) results and showed that the major diffraction lines were associated with the nitride phases. X-ray photoelectron spectroscopy (XPS) studies indicated the presence of Si3N4 and also small amounts of carbide which may be amorphous and possibly located at the grain boundaries. (c) 2004 Elsevier B.V. All rights reserved.