The Effect of Sand Particle Breakage on Tribological Properties of WC-9Co-5Cr-1Ni/Si3N4 Pairs Under Water Lubrication

In the field of deep-sea development, the external pressure is high. As a result, the filtration accuracy of the hydraulic system is limited. Aiming at a large amount of suspended sand in the ocean that the hydraulic components face, the tribological experiment under the simulated sand condition was carried out. A hard/hard pair of WC-9Co-5Cr-1Ni and Si
3
N4 was used to study the wear mode of WC coating under different sand particle sizes using 0.4% solution of three different quartz sand configurations, 6.5 μm, 38 μm, and 180 μm. In addition, under the condition of 180 μm solution with a concentration of 2%, by changing the normal load, the breakage of sand particles in the tribopair gap under different loading forces and the effect of sand breakage on the friction characteristics of materials were studied. The results showed that the particle size of 38 μmhas the most adverse effect on the friction coefficient, and the wear mode of WC coating was related to the particle size. Furthermore, the suspended sand was broken under a particular load, and the sand after fragmentation was beneficial to improving friction conditions. Experimental results may have certain reference significance for selecting tribopair materials of hydraulic equipment under the condition of suspended sand and heavy load.