Study On The Preparation And Tribological Properties Of PI Porous Materials Filled With PTFE/ACF/nano-Copper

With the development of modern science and technology,polymer matrix composites improve performance,it is gradually replacing part of the metal base material.Polyimide(PI)has excellent high and low temperature resistance,high mechanical strength,creep resistant capability is strong,and the advantages of stable chemical properties,application in automobile,electronics,aerospace and other fields widely.But the pure PI with larger friction coefficient and wear resistance is poorer,to overcome the above defects,often by filling different additives to improve the tribological properties of pure PI.In this paper,Based on PI substrate material filled polytetrafluoroethylene(PTFE),activated carbon fiber(ACF),nanometre copper(nano-Cu),by hot molding process preparing PI porous composites.Take the molding pressure,molding temperature,holding time,PTFE content,ACF content and Cu content as the main factors,using the orthogonal experiment method,setting test combination,to explore the preparation of PI best of porous composites molding process parameters and the optimal formula of three kinds of filler material;PI porous composites preparation and test its mechanical properties and tribological properties,analysis of PTFE,ACF,Cu content on the PI porous composite material mechanical properties and tribological performance influence;Measuring the porosity and oil absorption,confirmed after the oil properties and oiled tribology performance;Using the CSM reciprocating friction and wear testing machine PI porous composite material tribology experiment was carried out;Using 3 d white light scanner and scanning electron microscope(SEM)scanning PI worn surface porous compound material,get the wear surface 3 d the worn surface morphology,micro structure,and analyzes the mechanism of friction and wear.The results showed that the best sintering process of the PI porous composite material is molding temperature 360?,molding pressure 12.5MPa,50 min for thermal insulation and pressure.filled 20%PTFE,10%ACF 0.3%Cu as PI porous composites of the best comprehensive tribological properties.With 316 L steel mill the friction coefficient is about 0.1,about 1/4 that of pure PI.Wear rate is about 1/44 of the pure PI,has obvious antifriction effect;PI porous composites oil absorption rate increased with the increase ofACF content increases,the oil retention decreases with the increase of ACF.Oiled the tribology performance is also filled with 20%PTFE,10%ACF,0.3%Cu.With 316 L steel mill the friction coefficient is about 0.06,and the friction coefficient curve is very smooth,wear rate is lowest,about 1/2 of dry friction.Analysis suggests that PTFE is beneficial to the combination of ACF and PI,have synergy;"Ball" effect of nanometre copper to improve the wear ability of PI porous composite material.Pure PI wear mechanism are mainly adhesion wear,and wear mechanism of PI porous composites are mainly mild abrasive wear.