Tribological Properties of Fe-Al/WC Composite Coating Prepared by High Velocity Arc Spraying

FeAl coating and FeAl/WC composite coating were prepared on low carbon steel substrate by means of high velocity arc spraying. The friction and wear behaviors of the resulting coatings sliding against SAE5210 steel were examined on a T11 friction and wear tester, at ambient conditions and in a ballondisc contact configuration. The phase compositions and worn surface morphologies of the coatings were analyzed and observed by means of Xray diffraction and scanning electron microscopy together with energy dispersive spectrometry. The wear mechanisms of the coatings were discussed as well. The results showed that the FeAl/WC composite had better wear resistance than the FeAl coating, which was attributed to the loadcarrying and reinforcing function of the hard ceramic particles in the composite coating. The friction process could be divided into three stages corresponding to the runningin stage, the transition stage, and the steadystate stage, according to the variation of the friction coefficients with the sliding cycles. The composite coating was dominated by delamination wear in dry sliding against the steel. Both the friction coefficient and the wear rate of the coatings increased with increasing sliding speed, because of the accelerated crack propagation and frictioninduced thermal effect on the worn coating surfaces.