Papers by Author: S.H. Li

Abstract: In this paper described the possibility for using the copper nanoparticles as additives to lubricating oil. Copper nanoparticle has a decreased melting point and low shearing strength, therefore, the particles exhibit a high degree of slip. Adding copper nanoparticles to lubricating oil, can reduce the friction and wear of the friction surfaces, increase engine power, while reducing air pollution with an increase operating life of the engine. In this paper also described the liquid reduction process as a method for copper nanoparticle manufacture, which can be carried out without expensive special equipment. Generally in the process of gathering products – nanoparticles need to use the ultracentrifuge, and there is the phenomenon of aggregation of nanoparticles. In this paper obtained copper nanoparticles with dimensions of 30-80 nm without using the ultracentrifuge by adding organic solvent to a solution of the reduction reaction. Also presented the test results for friction and wear of the parts in the environment of the lubricating oil added copper nanoparticles. The experimental test results confirmed the theoretical assumption that copper nanoparticles improve the operational properties of the oil and reduce the abrasion of the surface of friction parts.

Abstract: One of the most applications of HIPSN(Hot-Isocratic Pressed Silicon Nitride) ceramic ball bearings is applied to the high-speed spindle of numerical control machine tools and high-speed precise mechanics. However, it is very difficult to process the HIPSN ceramic ball bearing. In this paper, a new grinding process method, taper rubbing method, is applied to process the HIPSN ceramic ball. Mechanical analysis of taper rubbing method is given, and the influence of grinding parameters on the ceramic material excision rate, surface quality of ceramic ball and wear and tear ratio of diamond wheel is studied by taper rubbing method. The experimental results show that the HISPN ceramic balls of G3 and G5 are obtained with taper rubbing method by properly controlling the motion of HIPSN ceramic balls and selecting reasonable processing technological parameters.