| As a new type of material,ionic liquid has the advantages of low volatility,non-flammability,high thermal stability,low melting point,excellent electrical conductivity and good solubility.Therefore,ionic liquids are electrochemically,organically synthesized,catalyzed and separated,and other fields are widely used.With the continuous research of ionic liquids by researchers,it is found that ionic liquids have great potential in friction lubrication.In this paper,ionic liquids were used as research objects to prepare ionic liquids.At the same time,the tribological properties of matrine-acid series ionic liquids as lubricants on copper,aluminum,316 stainless steel and titanium alloy substrates were studied.The results are as follows:(1)Study on the tribological properties of the friction pair of copper,aluminum,stainless steel and titanium alloy as a lubricant.The four ionic liquids of matrine series were synthesized.Using a reciprocating friction method,a series of ionic liquids were used as a lubricating medium using a pin-type friction tester,and the grinding balls were respectively tested on four friction substrates of copper,aluminum,stainless steel and titanium alloy using Si3N4.The friction performance was studied in depth.The order of thermal stability was found by TGA analysis:matrine dodecanoic acid ionic liquid>matrine ten acid salt ionic liquid>matrine eight acid ionic liquid>matrine six acid ionic liquid.The corrosion resistance of the ionic liquid was analyzed and the results showed that the four ionic liquid lubricants had little corrosion on copper matrix.Through the analysis of the wear scar volume,it is found that the order of wear scar wear volume from small to large is:copper<aluminum<316 stainless steel<titanium alloy.Through the comprehensive analysis of friction coefficient,wear scar wear volume,two-dimensional three-dimensional shape of wear marks and scanning electron micrograph,it is found that the lubricating properties of matrine lauric acid ionic liquid and matrine hexa-acid ionic liquid as lubricant are the best.This may be related to the length of the carbon chain in the ionic liquid,and the ionic liquid having a long carbon chain has better thermal stability and lubricating properties.(2)Four kinds of nano-copper/ionic liquid composite lubricants with two proportions were prepared and tribological wear experiments were carried out on 316 stainless steel and copper matrix.The thermal stability of the lubricant was analyzed and the results showed that the thermal stability of 1%nano-copper + matrine dodecanoic acid ionic liquid and 2%nano-copper+matrine dodecanoic acid ionic liquid was better than the other two kinds of cu ionic liquid.The corrosion resistance analysis of ionic liquid shows that the nanometer copper-ionic liquid composite lubricant has little corrosion on copper matrix.Comprehensive coefficient of friction,the wear and wear volume,grinding mark 3-d topography and SEM figure 2-d data,studies have shown that basic on the 316 stainless steel substrate all nano copper-ionic liquid lubricant has played a very good lubrication effect,the wear of wear volume compared with pure ionic liquid lubrication when got reduced greatly,this suggests that the nano copper additive added to the ionic liquid has played a certain decrease the effect of friction and wear,also further proves that this method is an effective way to reduce the wear and tear.(3)Four kinds of composite lubricants were prepared by using two kinds of synthetic ionic liquids as additives for gear lubricating oils.At the same time,the tribological properties were also explored by friction and wear experiments.Thermal stability analysis of the lubricant found that 20%matrine eight acid ionic liquid+lubricating oil and 50%matrine dodecanoic acid ionic liquid+lubricating oil two composite lubricants have good thermal stability,decomposition temperature is about 350? or so.Through the analysis of the friction coefficient,the surface morphology of the wear scar and the friction volume of the wear scar,etc.,20%matrine eight acid ionic liquid+lubricating oil and 20%matrine dodecanoic acid ionic liquid+lubricating oil are combined.The wear volume of the wear scar under lubricant lubrication is much lower than that of the pure ionic liquid lubrication,and the performance is better. |
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