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Tribology–Structure Relationships in Silicon Oxycarbide Thin Films
Author(s) -
Ryan Joseph V.,
Colombo Paolo,
Howell Jane A.,
Pantano Carlo G.
Publication year - 2009
Publication title -
international journal of applied ceramic technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.4
H-Index - 57
eISSN - 1744-7402
pISSN - 1546-542X
DOI - 10.1111/j.1744-7402.2009.02374.x
Subject(s) - materials science , tribology , composite material , silicon , lubrication , thin film , nanometre , sputter deposition , sputtering , modulus , silicon oxide , elastic modulus , nanotechnology , silicon nitride , optoelectronics
Silicon oxycarbide is a versatile material system that is attractive for many applications because of its ability to tune properties such as chemical compatibility, refractive index, electrical conductivity, and optical band gap through changes in composition. One particularly intriguing application lies in the production of biocompatible coatings with good mechanical properties. In this paper, we report on the wide range of mechanical and tribological property values exhibited by silicon oxycarbide thin films deposited by reactive radio frequency magnetron sputtering. Through a change in oxygen partial pressure in the sputtering plasma, the composition of the films was controlled to produce relatively pure SiO 2 , carbon‐doped SiC, and compositions between these limits. Hardness values were 8–20 GPa over this range and the elastic modulus was measured to be between 60 and 220 GPa. We call attention to the fit of the mechanical data to a simple additive bond‐mixture model for property prediction. Tribological parameters were measured using a ball‐on‐disk apparatus and the samples exhibited the same general trends for friction coefficient and wear rate. One film is shown to produce variable low friction behavior and low wear rate, which suggests a solid‐state self‐lubrication process because of heterogeneity on the nanometer scale.