Influence of WC carbide particle size on the microstructure and abrasive wear behavior of WC-10Co-4Cr coatings for aircraft landing gear

WC-Co-Cr thermal spray coatings are possible replacements for hard chrome plating on aircraft landing gear because of their superior wear resistance and environmentally friendly properties. In this study, four HVOF spray WC-10Co-4Cr coatings were deposited. During deposition, WC (tungsten carbide) particles were mixed into the coating. These included two types of single particle size distributions and two types of bimodal particle size distributions. The microstructure and abrasive wear behavior of these coatings were studied. The relationship among WC particle distributions, the deposit microstructure, and the three-body abrasive wear rates by rounded quartz grains was determined. The coating that only contained single particle size distribution of 1.2 μm-sized WC particles exhibited the best abrasive wear resistance.