The acid number of the mixed solution of 150SN oil and oleic acid characterizes the volume content of oleic acid in the solution, based on which the adsorptive capability of oleic acid is studied on the 45 steel balls...The acid number of the mixed solution of 150SN oil and oleic acid characterizes the volume content of oleic acid in the solution, based on which the adsorptive capability of oleic acid is studied on the 45 steel balls and disks. Boundary lubrication tests are carried out on a self designed ball-on-disk machine, The base oil is pure 150SN oil, and oleic acid as additive are added into the lubricant. Disks have surface roughness values （Ra） of 0.8 μn and 0.4 μn. The electrical contact resistance method is used to determine the lubrication status. Hypothesize that the molecular film is monomolecular layer in condensed state and the opposing surfaces are completely separated by molecular film. A boundary lubrication model is established according to experimental results and hypothesizes. The experimental and calculatienal results show that the adsorption of polar molecules on steel surface is the main factor to form the boundary lubrication film. Load and sliding speed contribute little to the friction coefficient of boundary lubrication. The properties of steel surface and additive for the lubricant significantly influence on the characters of boundary lubrication. The smaller the surface roughness value is, the smaller the friction coefficient of the boundary lubrication is.展开更多
Neodymium dialkylthiophosphate （NdDDP） with alkyls of isopropyl and isooctyl were synthesized by exchanged reaction respectively. The structures of the two NdDDPs were determined using IR and XRD. Properties of anti...Neodymium dialkylthiophosphate （NdDDP） with alkyls of isopropyl and isooctyl were synthesized by exchanged reaction respectively. The structures of the two NdDDPs were determined using IR and XRD. Properties of anti-wear and friction-reducing of the two additives were investigated with four ball experiment and the commercial anti-wear additive ZDDP was selected as control. The elemental analysis of the wear scars after 10 s friction at low stress were investigated by EDXA （Energy Dispersion Analysis of X-ray）. Primary results showed that the NdDDPs possess better lubrication ability than ZDDP. This might mainly be contributed to the formation of a boundary film containing Nd2O3, FeS and sulphate, phosphate, organo-sulfide, etc., and a neodymium-rich diffused layer which changes the crystal structure of the surface of friction materials.展开更多
This paper attempted to solve the problem of scuffing mechanism on the basis of the-ories in three fields: Boundary lubrication , Hydrodynamic lubrication and Surface contact. forlineasr contacting, a simple solution ...This paper attempted to solve the problem of scuffing mechanism on the basis of the-ories in three fields: Boundary lubrication , Hydrodynamic lubrication and Surface contact. forlineasr contacting, a simple solution has been obtained.展开更多
基金This project is supported by Specialized Research Fund for Doctoral Program of Higher Education, China(No.20030561007)
文摘The acid number of the mixed solution of 150SN oil and oleic acid characterizes the volume content of oleic acid in the solution, based on which the adsorptive capability of oleic acid is studied on the 45 steel balls and disks. Boundary lubrication tests are carried out on a self designed ball-on-disk machine, The base oil is pure 150SN oil, and oleic acid as additive are added into the lubricant. Disks have surface roughness values （Ra） of 0.8 μn and 0.4 μn. The electrical contact resistance method is used to determine the lubrication status. Hypothesize that the molecular film is monomolecular layer in condensed state and the opposing surfaces are completely separated by molecular film. A boundary lubrication model is established according to experimental results and hypothesizes. The experimental and calculatienal results show that the adsorption of polar molecules on steel surface is the main factor to form the boundary lubrication film. Load and sliding speed contribute little to the friction coefficient of boundary lubrication. The properties of steel surface and additive for the lubricant significantly influence on the characters of boundary lubrication. The smaller the surface roughness value is, the smaller the friction coefficient of the boundary lubrication is.
文摘Neodymium dialkylthiophosphate （NdDDP） with alkyls of isopropyl and isooctyl were synthesized by exchanged reaction respectively. The structures of the two NdDDPs were determined using IR and XRD. Properties of anti-wear and friction-reducing of the two additives were investigated with four ball experiment and the commercial anti-wear additive ZDDP was selected as control. The elemental analysis of the wear scars after 10 s friction at low stress were investigated by EDXA （Energy Dispersion Analysis of X-ray）. Primary results showed that the NdDDPs possess better lubrication ability than ZDDP. This might mainly be contributed to the formation of a boundary film containing Nd2O3, FeS and sulphate, phosphate, organo-sulfide, etc., and a neodymium-rich diffused layer which changes the crystal structure of the surface of friction materials.
文摘This paper attempted to solve the problem of scuffing mechanism on the basis of the-ories in three fields: Boundary lubrication , Hydrodynamic lubrication and Surface contact. forlineasr contacting, a simple solution has been obtained.
