| Poor wear resistance is the inhibition of titanium in aerospace and automotive industry and other fields, but through the surface treatment can improve the surface wear resistance. Micro-arc oxidation (MAO) technique is a new kind of surface treatment method for nonferrous metals, and it can fabricate an in-situ ceramic coating on the nonferrous metals such as aluminum, magnesium, titanium and their alloys. Ceramic coatings with good wear resistance were successfully fabricated on Ti6Al4V-ELI using MAO method with both alternative and direct current power source. This research was of great significance on the application and development of MAO method in the long run.In the micro-arc oxidation ceramic coating preparation, two electrolyte systems on Ti6A14V with good results were developed. Towards intermeiate temperature wear property, the following points are cruical:the difference of the thermal expansion of the substarte and coating, the hardness and the interficial adhesion. Based on these, the samples were oxidized in tow separatory electrolyte so as to prepare the middle and outer layer.Constant voltage DC power supply was used to fabricate intermediate layer processing. Adjusting frequency and duty cycle can require a set of suitable parameters with good quality. The outer hard layer is obtained by constant current power supply, and the alternative constant current source can be used to better control the surface roughness and thickness due to its duty cycle.The influence of oxidation time and the additives was discussed.The surface of the composite coating shows a vocanic like stucture, and XRD patterns reveals that ceramic layer mainly composed of t-ZrO2,m-ZrO2,Al2TiO5 andγ-Al2O3. The composite coating is not mechanical combination but through the diffusion. Thus, it has a good adhesion.Towards to the intermeidate wear prperty, this kind of coating has lower friction coefficient, and with processing time going the friction coefficient decreases. Good toughness and the porous structure plus high hardness make the coating good wear resistance performance. In addition, the thermal expansion of the middle layer is between the outer layer and the substrate. At that atmosphere, this strcture would decrease the compressive stress. The research shows:the main types of the friction are adhesion wear and abrasive wear. GCr15 can transfer to another part, in experimental conditions, oxidation of the particles and the fatigue wear in some lower spot is also obvious. The friction coefficient kept a stable decrease with the distance going. When changing load and speed, the samples were made to increase wear rate and friction coefficient, but the overall trend is similar.
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