| Attapulgite (ATP) is widely used in petroleum, chemical industry, building materials, medicine and agriculture, due to its unique microstructure, excellent physiochemical properties and environment-friendly features. It has been gradually attracted as the composition of the grease. In this thesis, the grease was prepared using modified ATP as the thickener. The effects of different cationic surfactants, as well as several oxide additives on the tribological properties are investigated. Main contents are summarized as follows:1. ATP was modified by four cationic surfactants. The grease was prepared using modified ATP as the thickener, and its tribological properties were tested. The results show that the structures and properties of the cationic surfactants have a great influence on the performance of the grease, in which didodecyldimethylammonium bromide and cetylpyridinium bromide grease possess better anti-wear and friction reducing properties.2. ZnO and Cu/ZnO nanoparticles were synthesized by ethanol thermal method and characterized. The effects of nanoparticles as the additive on the grease were researched. The results show that nanoparticles from different Zn source have a great impact on the performance of the grease. The rod-shaped ZnO, the best dosage of which is2%, is superior to the granular ZnO on the anti-wear and friction-reducing properties. Moreover, the dosage of ZnO as additive is reduced (the optimal dosage of1%Cu/ZnO and5%Cu/ZnO is1%and5%, respectively. Due to the modification of Cu, the anti-wear property of the grease is enhanced, especially in the high load.3. Three kinds of dioxide nanoparticles are selected as the additives of the grease, the effects of which on the tribological properties are investigated. The results show that the anti-wear property of SiO2is greatly superior to TiO2and ZrO2, especially at high load. The best results are achieved when the content of SiO2is2%. |
