Influence of nozzle configuration and particle size on characteristics and sliding wear behaviour of HVAF-sprayed WC-CoCr coatings

In this study, effect of feedstock particle size and nozzle configuration on deposition, microstructural features, hardness sliding wear behaviour high velocity air fuel (HVAF)-sprayed WC-CoCr coatings was evaluated. Three different powders with nominal sizes 5/20 ?m (fine), 5/30 (medium) 15/45 (coarse) were sprayed employing a HVAF gun four distinct DeLaval configurations involving lengths and/or exit diameters. Microstructure, phase constitution mechanical characteristics the evaluated using SEM, EDS, XRD micro indentation testing. Specific rate for all samples determined under conditions comprehensive post analysis conducted. X-ray diffraction showed negligible decarburization in HVAF-sprayed coatings. It shown that decrease employed results discernible changes features as well considerable improvement their performance. Also, notable mechanisms identified reducing from coarse to medium or fine. Fine found be sensitive type used while no major difference observed cut nozzles.