Study On Friction And Wear Performance Of WC-Co Cemented Carbide

High-pressure water jet rotating nozzle is valued for its high crackdown and satisfactory cleaning effect.As a key component of high-pressure rotary nozzle,the suitable collocation of nozzle-core assembly's materials is particularly important to improve the service life of the nozzle.The friction and wear performance of cemented carbide / cemented carbide and cemented carbide / ceramic friction pairs were studied.Meanwhile,the influence of WC-Co cemented carbides' microstructure on its friction wear properties was analyzed.The friction and wear tests have been examined in reciprocating sliding wear experiments using a HSR-2M high-frequency pin-on-plate system.The plate is WC-11.6 wt.% Co cemented carbide with a WC mean grain size of 0.77 ?m,and the pin is YG6 X cemented carbide ball and Si3N4 ceramic ball,respectively.The sliding distance,load,reciprocating speed and surface roughness of the specimen are the main influencing factors.The suitability of the two types of friction pairing is judged by comparing the wear volume and the wear rate of the specimen.The results show that the wear resistance of cemented carbide is affected significantly by mating material,and the wear resistance of cemented carbide / cemented carbide friction pair is much better than that of cemented carbide / Si3N4 ceramic friction pair.Wear of the cemented carbide / cemented carbide friction pair less affected by the load and reciprocating speed.While,the change of load and reciprocating speed has a significant effect on the wear of cemented carbide / Si3N4 ceramic friction pairs.Its wear volume increases linearly with the increase of load and reciprocating speed.A series of WC-Co cemented carbide samples with different WC grain size or Co phase content were prepared and tested by friction and wear tests with YG6 X cemented carbide balls.The effects of the microstructure on the friction and wear performance of WC-Co cemented carbides were investigated.The wear mechanism of the friction pair was studied by scanning electron microscopy,X-ray energy spectrum and ultra-depth optical microscope.The results show that the microstructure of cemented carbides have a great influence on the wear performance of WC-Co cemented carbides.The wear increased with both Co content and WC grain size.The wear mechanism of the cemented carbide / cemented carbide friction pairs is mainly scratch,fragmentation and breakaway of the WC grains and smearing of the Co phase.The load has a significant effect on the wear mechanism of cemented carbides,and the wear mechanism of cemented carbides is scratched when the normal load is small.With the increase of the normal load,the wear mechanism of cemented carbides gradually changed to the furrow,fragmentation and breakaway of WC grain,and removal of binder phase from the surface layer.Nozzle-core assemblies with WC grain size of 0.6 ?m and Co content of 6 wt.% were fabricated and tested on a high-pressure water jet washer.Application of examination shows that the nozzlecore assembly can meet the cleaning requirements commendably.