Study On Preparation And Properties Of Graphite Solid Lubricating Composites

Graphite is used in the lubrication of mechanical equipment and processing technology in various forms,which can reduce friction and wear and improve production efficiency.In this paper,graphite was used as lubricant to combine with resin,molybdenum disulfide and copper,and thus preparing graphite-resin lubricating coating,graphite-molybdenum disulfide solid lubricating material and copper-based graphite composite lubricating material,respectively.The mechanical properties and tribological properties of graphite-based composite lubricating material were studied,and the lubricating mechanism was discussed by analyzing the wear surface.The main work and conclusions are as follows:?1?The prepared graphite-resin lubricating coating was coated on the surface of the friction ring,the composition ratio of the lubricant coating with the best anti-wear and friction-reducing performance was determined by orthogonal test,that is,graphite?7g?/ethyl cellulose?8.5g?/OP-10?2g?/isopropanol?270g?.The relationship of the average friction coefficient of the lubricating coating under different loads is?_50N>?_10N>?_30N,and that under different rotating speeds is?_100r/min>?_300r/min>?_200r/min;the wear mechanisms of the lubricating coating at different friction stages include plastic deformation,fatigue wear and abrasive wear;and the lubricating coating can effectively improve the corrosion resistance and mechanical properties of the material.After bending of 1 mm shaft rod and impact of 50 cm ball dropping,it has no falling off,the adhesion is grade 6 and the hardness is H.?2?The prepared graphite-molybdenum dioxide solid lubricating material was filled into the drilling hole of the friction ring,the composition ratio of the lubricant material with the best anti-wear and friction-reducing performance was determined by orthogonal test,that is,molybdenum dioxide?5g?/graphite?2.5g?/epoxy resin?30g?/Polyamide?20g?.The relationship between the average friction coefficient of the coating under different loads is?_50N>?_10N>?_30N,and the rotating speed is proportion al to the friction coefficient.The wear mechanism study shows that molybdenum dioxide and graphite are bith the effective anti-wear and friction reducing components of the lubricating material,which have synergistic lubrication effect.The wear mechanism in different friction stages mainly includ es plastic deformation,fatigue wear,abrasive wear and so on.?3?Graphite/copper composite?GP/Cu?and carbon coated graphite/copper composite?CCG/Cu?were prepared by powder metallurgy.The comparative analysis of microstructure shows that the resin can im prove the surface properties of natural graphite,and high-temperature calcination can accelerate the sintering of Cu particles in CCG/Cu,and form a continuous network shape isolation layer,so it has better physical and mechanical properties.The tribolo gical performance of CCG/Cu is better than that of GP/Cu,because the agglomeration of graphite particles in GP/Cu will cause the fracture of the interface and the rupture of the lubricating film,thus leading to the deterioration of the anti-wear and friction-reducing performance;the phenolic resin coating in CCG/Cu can remove the defects on the surface of natural graphite,and protect the surface structure by reducing graphite peeling,so as to improve its anti-wear and friction-reducing performance.