Preparation And Tribological Properties Of Silver Pyrazole Methylpyridine Additives

Modern large-scale mechanical equipment is developing in the extreme direction of high speed and heavy load,which places higher requirements on the anti-wear and anti-friction performance of lubricating oil.As such equipment usually works in high temperature and polluted environment,it is affected by the deterioration and failure of lubricating oil caused by high temperature,as well as the impact of dust,dirt and mechanical processing debris entering the oil lubrication system and resulting in wear and tear.The performance of lubricating oil and its additives is severely challenged,so it is necessary to study the high-performance lubricating oil additives applicable in a wide temperature range.This paper aims to study the tribological properties of lubricating oil additives for harsh working conditions,and to conduct friction and wear tests of silver pyrazole pyridine lubricating additives suitable for high temperature and polluted environments.Research and analysis of the friction and wear characteristics of this lubricating additive over a wide temperature range.The main content and conclusions of the full text include:(1)Three kinds of silver pyrazole and pyridine complexes with light stability and air stability were synthesized to obtain a series of silver pyrazole and pyridine complexes with different structures and sizes.XRD and SEM were used to characterize the micro-morphology and phase composition of the product.The results show that the purity of the three preparation products is relatively high.Among them,silver complex 1 is a cylinder with a diameter of about 2μm and a length between 10μm-40μm;silver complex2 is a sphere with a diameter of about 1μm;and silver complex 3 is Spherical structure with a diameter of about 10μm.(2)The thermogravimetric analysis of the series of silver complexes was conducted to master the release rule of silver particles in the series of complexes under high temperature conditions.Silver complex 1 showed its first weightlessness at 239℃.The silver complex 2 decomposed for the first time at 110℃-150℃,with a weight loss of5.97%,and for the second decomposition at 230℃-250℃,with a weight loss of 6.18%.The silver complex 3 is pyrolyzed in a single step of 210℃-248℃,and the accompanying weight loss is 32%,which is consistent with the weight percentage of pure silver of 28.7%,and the other 3.3% should be crystal water and broken complex quality.In addition,the XRD comparison of the thermogravimetric residual material with the standard card of pure silver also proved that the silver pyrazole-methylpyridine complex produced silver elemental substance at high temperature.(3)The prepared series of silver complexes are added to the base oil in a certain proportion,and the lubricating performance is tested on a friction tester.The test is continuously heated from room temperature to high temperature,and the high temperature test is performed at the critical point of high temperature according to the result of thermogravimetric analysis.The mass percentages of additives in the lubricating oil are0.5%,1.5% and 2.5%,respectively,and a set of control tests without additives.After the friction and wear test was completed,the data and wear scars were analyzed to discuss the anti-friction mechanism and optimal ratio of the three silver complexes as additives at different amounts.The results showed that the three silver complexes showed the best anti-wear and anti-friction performance when the added amount was 0.5wt.%.Among them,the silver compound 3 as the additive has the smallest wear rate,which is 45.3%lower than that of the base oil.The tribological mechanism shows that in the lubricating oil containing the silver complex additive in a high-temperature environment,there is indeed a lubricating oil film formed during the friction on the surface of the friction pair,and silver particles are present in the oil film,thereby reducing friction and wear.There are 43 figures,7 tables and 85 references in this paper.