Comparative study of microstructure and tribological behavior of TiC/a‐C:H and a‐C:H coatings in a sand‐dust environment

Abstract

TiC/a-C : H and a-C : H nanocomposite coatings were prepared on AISI 440C steel substrates using magnetron sputtering process. A comparative study was made on their composition and microstructure by Raman spectroscopy and high-resolution transmission electron microscopy (HRTEM). The tribological properties of two types of carbon-based coatings were investigated by pin-on-disc tribometer under the sand-dust conditions concerning the influence of applied load, amount of sand and sand particle sizes. The results show that these carbon-based coatings exhibited high tribological performance with low friction coefficient and wear rate under the sand-dust environments. However, the TiC/a-C : H coatings exhibit relatively higher fluctuant friction coefficient as well as higher wear rate in comparison with the a-C : H coatings under sand-dust environments. The formation of nanocrystalline hard TiC phase distributed in amorphous carbon matrix decreased the residual stress but significantly increased the hardness and Young's modulus of TiC/a-C : H coatings, and consequently caused a relatively higher abrasive and fatigue wear loss under the sand-dust conditions.

Molecular dynamics study on tribological behaviors of DLC films

“…This is because the large-sized particles can roll easily during the friction process while also causes a high contact stress to the films and thus cause their severe abrasive wear (Qi et al, 2011a). It has been found that a high load can reduce the wear rate of the films by causing the fragmentation of the sand particles (Qi et al, 2011b).…”