Friction and Wear Properties of SiC-Ti and SiC-Al Films Deposited by Simultaneous RF Magnetron Sputtering

Abstract

In order to improve friction and wear properties of amorphous SiC film deposited on titanium substrate specimen, Ti or Al was added in SiC film by simultaneous sputtering of SiC and Ti or Al targets using a dual-cathode RF magnetron sputtering apparatus. Wear tests were carried out on the specimens using a ball-on-disk type testing apparatus with SiC ball. The result shows that the addition of a certain amount of Ti or Al decreases wear rate of SiC film and increases the number of rotation cycles to delamination. When the Ti concentration is 2.6 at.%, the friction coefficient decreases to a minimum value of 0.04, which is about a half of SiC film without Ti and diamond-like carbon (DLC) film. This lower friction coefficient of SiC-2.6%Ti film than DLC film is obtained also for other ceramics and metal balls. The SiC-1.5%Al film reveals higher wear resistance than the SiC or SiC-Ti films with low friction coefficient of 0.1. Observation of wear scar in the film and SiC ball during the wear test implies that wear debris plays an important role in reducing the friction coefficient. Nano-indentation tests shows that the stiffness and elastic modulus of SiC-1.5%Ti and SiC-3.6%Ti is the largest among other SiC films with different Ti or Al content.