Study On The Synthesis Of Serpentine Used For Lubricant Additives

Serpentine have agood tribological properties as lubricant additives,its role in the in-situ repairing of machine parts can reduce the loss of parts to save energy,is an environmentally friendly self-repairing additives.The synthesis of serpentine were performed with several experimental programs,different experimental conditions and composited with other components in this paper.The synthesized products was modified and added to the base oil and the tribological properties were tested by four-ball friction and wear test.The main contents are as follows:The preparation of serpentine by hydrothermal synthesis was carried out using nano-SiO2 and MgO,nano-SiO2 and MgO prepared by special liquid-phase precipitation MgO,talc and MgO as reactants.The results showed that chrysotile nanotubes with good crystallinity and good dispersibility were successfully synthesized from talc and MgO.The results have shown that the temperature is a crucial factor for the growth of chrysotile nanotubes.The higher the temperature is good for the growth of chrysotile nanotubes.In addition,the initial reactant species also have some influence on the synthesis of chrysotile.The synthetic products of talc and MgO and natural serpentine were modified by modifier and were added to the base oil as lubricant additives,four-ball friction and wear testing machine were used to test the tribological properties of powders.The results show that the natural serpentine has a certain anti-friction and anti-wear effect,but the effect is not better than synthetic serpentine.The natural serpentine powder can reduce the friction coefficient and the wear spot diameter by 10%and 3%respectively,while the hydrothermal synthetic products of talc and MgO can reduce the friction coefficient and the wear spot diameter by 28-38%17-26%,and synthetic products containing more chrysotile can increase the anti-friction effect.Chrysotile/Fe3O4 composited powder and Fe-doped chrysotile powder were successfully prepared by coprecipitation and hydrothermal synthesis methods.The experimental results show that the Fe composited products of coprecipitation can make the friction coefficient reduced by 55%and the diameter of the wear scar reduced by 58%compared to the base oil.The analysis of the wear surface shows that coprecipitation synthesized Fe3O4 of can prevent further contact with the friction pair and play a good anti-friction and anti-wear effect.Compared with coprecipitation method,the friction effectiveness of hydrothermally Fe doped products as lubricant additives is obviously better.Compared with the base oil sample group,the friction coefficient can be reduced by 66%and the diameter of the wear spot reduced by 64%.Compared with the non iron sample,the friction coefficient and the wear spot diameter can reduced by both 55%,55%.The analysis of the wear surface shows that the anti-friction and anti-wear effectiveness of the Fe-doped chrysotile as lubricat additives does not always increase with the increase of Fe content.During the friction process,the additives can forms an anti-friction film on the worn surface due to the chemical action,which prevents abrasion of the friction pair.