Influence of CH4 Flow Rate on Microstructure and Properties of Ti-C:H Films Deposited by DC Reactive Magnetron Sputtering

Abstract

ABSTRACTNanocomposite Ti-containing hydrogenated carbon films (Ti-C:H) were prepared using a DC reactive magnetron sputtering system. The relationship between CH4 flow rate and the film characterization and tribological behaviors in both ambient air and deionized water conditions were investigated. Results showed that the Ti content in the as-deposited Ti-C:H films decreased and the sp3 content increased with an increase in CH4 flow rate. TiC nanocrystallites can be formed at a relatively low CH4 flow rate, whereas there was almost no formation of TiC in the amorphous carbon matrix at the highest CH4 flow rate. The hardness, elastic modulus, and internal stress of the films were decreased firstly and then increased as the CH4 flow rate increased, whereas their adhesion presented an inversely changing trend. The friction coefficients and wear rates of Ti-C:H films in both ambient air and deionized water conditions decreased with increasing CH4 flow rate from 8 to 12 sccm and then increased as the CH4 flow rate continually increased. In particular, the nanocomposite Ti-C:H film deposited with a CH4 flow rate of 12 sccm could achieve superior combining mechanical properties and low friction and high antiwear behaviors in both ambient air and deionized water conditions, indicating potential applications as a protective and lubricating film for mechanical components.