Study On Honeycomb Building And Preparation Of MAO-PTFE Self-lubricating Composite Membrane On The Surface Of Aluminum

With the development of modern industrial technology,the demands for aluminum and its alloy which has the advantages of rich resources and low price are becoming increasing,anti-wear and friction material is also becoming widely applied.The objective of this paper is to prepare a new type self-lubricating aluminum matrice with good combination and excellent tribological performance.Firstly,establishing honeycomb on the surface of aluminum was carried out by using special honeycomb preparation machine,examined the influence of punching pressure,hole spacing on size and deformation degree.Secondly,the ceramic treatment for the samples with different construction parameters was conducted with micro-arc oxidation(MAO)technique,then,inspected the influence of honeycomb on the process of MAO,the properties and morphology of the MAO film.Again,PTFE was filled into the honeycomb with MAO film in order to make the comparison of the diverse filling methods.Analysing the filling efficiency comprehensively after the honeycomb was filled by using "static spray-rolling".Finally,the sliding dry friction and wear test was carried out by the pair of ring-block surface to study the influence of honeycomb on MAO film and MAO-PTFE composite membrane,compare the friction performance of different hole spacing.The results show that,complete honeycomb can be built on the surface of aluminum,compared with the punching pressure,hole spacing has little impact.Uder the same hole spacing,with the increase of punching pressure,the average size of honeycomb and the degree of deformation are magnifying,the grain size of deformation layer is decreased.Sample rushed honeycomb in central part appeared the phenomenon of point discharge during MAO.Under the same condition of MAO,the sample has honeycomb can start arcing in advance under lower voltage and has MAO film thicker and harder.With the punching pressure increasing,the effect is more significant.Observe the surface morphology after MAO,the sample rushed honeycomb has more discharge pores and smaller surface oxide particles.Filling PTFE into honeycomb to preparate self-lubricating composite membrane by using static spray-rolling is better than direct pressure and dip-coating,its filling surface level off and has less bubbles.When the punching pressure achive at 0.4 MPa,honeycomb can be filled effectively by using static spray-rolling method,but when the pressure is lower than this level,more bubbles appear.After the PTFE composite processing,the surface morphology is smooth and beomes level off.With the increase of hole spacing,the flatness of sample surface increases,the filling rate of single honeycomb also increases.Friction experiment on the sample that has MAO film and MAO-PTFE composite membrane was carried out,the test results indicate that the existence of honeycomb can prominently improve the wear resistance.At the same condition,with the decrese of hole spacing,wear resistance strengthens and surface crack decreases.Compare the sample with honeycomb after PTFE composite treatment,the friction coefficient remarkable reduces,wear resistance strengthens and less surface cracks,wear tracks.