A review of nanocrystalline diamond/β-SiC composite films

Abstract

The idea behind synthesis of nanocrystalline diamond/β-SiC composite films is to obtain films those posses a whole range of combined properties of diamond and β-SiC to serve tribological, thermal barrier, electronics and biological applications. The diamond/β-SiC nanocomposite films are designed in such a way that the resultant material contains required volume of nanometer sized grains of both the components such that the availability of large volume of grain boundaries can be controlled based on the application requirement. In this paper a review of nanocrystalline diamond/β-SiC composite film system with regards to its controlled synthesis, characterization, mechanical properties, and coefficient of friction will be discussed. Microwave plasma enhanced chemical vapor deposition technique was used to carry out the nanocomposite film depositions with the aid of H2-CH 4-Si(CH3)4 gas mixtures. Based on the micro-structural analyses these nanocomposite films are classified as granular type composite films that contain diamond and β-SiC components as nanocrystalline grains distributed contiguously and laterally throughout the thickness of the film in a desired volume fraction combinatorial form. Deposition of gradient natured diamond/β-SiC nanocomposite films and novel diamond/β-SiC composite films containing (001) diamond rounded or square faceted surfaces will also be discussed. β-SiC content and diamond microstructure in the films are identified as the compositional and structural factors respectively that influence the mechanical and friction properties.