Dispersion effect and auto-reconditioning performance of nanometer WS2 particles in green lubricant

This paper reported on dispersion effect and dispersing techniques of nanometer WS2 particles in the green lubricant concocted by us. And it also researched on auto-reconditioning performance of nanometer WS2 particles to the abrasive surfaces of steel ball from four-ball tribology test and piston ring from engine lubrication test. The treated and untreated nanometer WS2 particles were analysed by infrared spectrum. And the elementary component and interior elementary distribution of abrasive surface repaired by nanometer WS2 particles were analysed by multifunction electron spectrometer. The results showed that the combinative method of ultrasonic dispersion, mechanical agitation and surface modification could improve the dispersion uniformity and stability of nanometer WS2 particles in the green lubricant effectively. And the optimal ratio of the mass between surface modifier and nanometer WS2 particles was 1: 2.5, the optimal treating time was 5 h. And IR analysis indicated that surface modifier could react with hydroxide radicals on surfaces of WS2 particles and modify the surfaces, and the long lipophilic groups on surfaces of nanometer WS2 particles could stretch in oil adequately and form steric hindrance layers between particles which prevented particles from conglomerating and depositing. In addition, tribological tests and surface analysis indicated that there were WS2 adsorption film and reaction film on abrasive surfaces during the tribological tests, which could fill and level up the furrows on abrasive surfaces. As a result, the abrasive surfaces were repaired effectively by nanometer WS2 particles.