Study On Preparation And Properties Of Self-healing Wear-resisting Ceramic Layer On Diesel Aluminum Alloy

Application of Aluminum alloy in ship diesel engine piston was important,but its surface hardness,wear resistance,corrosion resistance and other defects on properties restricted its wide usage,so,surface strengthening treatment was needed.Ceramic layer with properties of high hardness,wear resistance,corrosion resistance on aluminum alloy surface layer can be perpetrated by Micro-arc oxidation technology.After repair of,can be a layer of properties of wear resistant ceramic layer with character of self-healing formed after micro-nano self-healing particles serpentine with property of was added in the electrolyte.The optimized scheme of electrolytic parameters and power parameters was designed by using the orthogonal experiment,the surface morphology of the film,the cross section morphology and element composition was explored by using scanning electron microscopy(SEM),the film thickness,roughness,micro hardness was measured,the friction and wear test was carried out,the optimum parameters of preparation of ceramic layer was determined;of the serpentine nano particles was prepared by using high-energy ball-milling technique,then serpentine powder was added into the electrolyte and micro-arc oxidation experiment was carried out in order to get composited ceramic layer which contains serpentine micro/nano particle,after that the concentration of the serpentine was optimized;Through the analysis of membrane layer before and after the friction and wear test and element composition,the self-healing properties of film layer was studied.The optimization of electrolytic parameters and power parameters was designed by using the orthogonal experiment.Final optimization of.by considering the index of ceramic membrane film thickness,hardness,roughness and surface morphology and cross section morphology index,and the parameters of the power supply and electrolyte was finally optimized.The parameters of the electrolyte is:the concentration of sodium silicate is 8 g/L,potassium hydroxide concentration is 2.5 g/L,concentration of sodium tungstate is 5 g/L,2 g/L EDTA;Power supply parameters:forward voltage is 420 V,a negative voltage is 130 V,the duty ratio is 20%,frequency of 500 Hz,oxidation time is 1 h.According to the optimal parameters,the ceramic layer has optimal performance,when the concentration of serpentine is 6 g/L.In meager oil condition,Si element which is contented in the composited ceramic membrane increased,during the friction and wear test.The friction surface generated a layer of protective film,showing that the preparation of the composite ceramic membrane has good self-healing capacity.