Properties of wear-resistant WC-10Co-4Cr coatings prepared by high velocity oxy-fuel thermal spraying
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https://doi.org/10.54939/1859-1043.j.mst.FMC.2026.45-52Keywords:
WC-10Co-4Cr; HVOF.Abstract
This study aims to investigate and evaluate the microstructural characteristics, microhardness, and porosity of wear-resistant WC-10Co-4Cr cermet coatings deposited by high-velocity oxy-fuel (HVOF) thermal spraying. The methodology involves analyzing the morphological evolution of commercial cermet feedstock powder (with a particle size range of 15 – 45 µm) before and after interacting with the combustion gas stream (oxygen/propane) using scanning electron microscopy (SEM). The interface structure between the coating and the steel substrate, as well as the correlation between coating thickness and microhardness, were also investigated. The results indicate that under the high-temperature and supersonic velocity conditions of the HVOF spraying process, the initially porous cermet powder underwent surface densification. Concurrently, fine particle fragmentation occurred, leading to a decarburization reaction and the formation of the W2C phase, a trend that significantly intensified at an oxygen/propane ratio of 300/55. At the interfacial boundary, the coating exhibited strong and sustainable bonding with the steel substrate. The coatings achieved excellent densification, with the porosity maintained at a very low level of 1% to 2%. The average microhardness of the entire specimen reached a high value of 628.86 HV, an adhesion strength of 63.2 MPa and a sliding wear rate of 1,65 x 10-5 mm3/N.m for the sample with the highest hardness.
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