Research On Aluminum Alloy Brake Disc Micro-arc Oxidation Coating Treatment Process And Its Properties

A new generation of green energy-saving aluminum brake disc was used for electric vehicles,which was used to solve the parking between brake parts under the condition of rust or adhesion phenomenon.But aluminum alloy brake disc has low hardness,poor wear resistance and corrosion resistance,high temperature properties and thermal shock resistance is weak,as well as its weak temperature resistance and thermal shock resistance.In order to improve its service life and service safety,a micro-arc oxidation ceramic film(MAO film)was successfully prepared on the surface of a A356 material sample.The thermal shock resistance of the ceramic film and its friction matching performance with a synthetic brake pad material were also studied,And the following main research results are obtained.A356 aluminum alloy as substrate,the test of electrolyte and electrical parameters in order to optimize the factors,with MAO layer thickness,surface roughness,cross-section microhardness comprehensive status as the optimization goal,experiment using orthogonal test method,studied the relation of experimental optimization factors and the optimization goal,found a better test of electrolyte and electrical parameters.The thermal shock performance of the applied MAO film was using both thermal shock test which took crack and spalling of ceramic film as the judgement standard.MAO layer is studied under different thermal shock temperature range,different thickness of MAO layer,thermal shock performance under different thermal shock cycles.The results show that the MAO film has good thermal shock resistance.Under thermal cycling conditions of 30°C-300°C,60 ?m thick MAO films can bear 1000 times circulation without micro-peeling.Based on the shrinkage ratio friction test,the friction matching performance between MAO film and synthetic brake pad material under dry friction.The results show that,MAO film can protect the matrix,ease the temperature rise of the matrix and stabilize the friction coefficient.The friction and wear mechanism of MAO film was discussed according to the morphology of friction surface under different test conditions.The research results of this paper can provide scientific guidance regarding maintenance schedules and the service safety of A356 Aluminum alloy brake disc and play an instrumental role in promoting its industrial application.