Structure and mechanical properties of Ti-Si-C coatings deposited by magnetron sputtering

Abstract

Nanostructured coatings consisting of mixed carbide phases can provide a potential means to developing superhard coatings. Heterogeneous nanostructured coatings can be obtained by either deposition of multilayer structures or by depositing film compositions that undergo a natural phase separation due to thermodynamic immiscibility. In the present work, we have taken the latter approach, and deposited films by radio frequency cosputtering from dual carbide targets. We have examined a number of ternary carbide systems, and here we report the results obtained on Ti-Si-C films with a nominal (Ti1-xSix)C stoichiometry and with x less than or equal to0.31. It was found that the nanoindentation hardness increased with Si content, and the maximum hardness achieved was nearly twice that of sputter-deposited TiC. We further analyzed these films using high-resolution transmission electron microscopy (TEM), x-ray photoelectron spectroscopy (XPS), and x-ray diffraction. Since cubic SiC has an x-ray pattern almost identical to that of TiC, the extent of phase separation could not be determined by that method. However, XRD did demonstrate a general disordering of the films with increasing SiC content. In addition, a mottled structure was observed in high-resolution TEM images of the Si-containing films, confirming microstructural effects due to the Si additions. (C) 2001 American Vacuum Society.

Department

Mechanical Engineering

Publication Date

4-1-2001

Journal Title

Journal of Vacuum Science & Technology A

Publisher

AMER INST PHYSICS

Digital Object Identifier (DOI)

10.1116/1.1379322

Document Type

Article

Rights

Copyright 2001 American Vacuum Society. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Vacuum Society.

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