加压时间间隔对AZ91D镁合金微弧氧化膜的影响

Effects of interval of enhancive voltage on micro-arc oxidation coatings of magnesium alloy AZ91D

研究硅酸盐体系中加压时间间隔对AZ91D镁合金微弧氧化膜层的影响.利用TT230数字式涂层测厚仪、JSM—6700F扫描电子显微镜、2206型表面粗糙度测量仪(E34—001)和W—92涂层附着力划痕试验机研究了其微观结构,利用CHI660C电化学工作站和UMT—2MT型球-块往复式摩擦试验机进行耐蚀性和耐磨性的评定.结果表明,微弧氧化膜层的厚度、粗糙度和结合力随着加压时间间隔的增大而增大;孔隙率呈先增大后减小的趋势,在加压时间间隔为150s时出现了最大值;与基体相比,微弧氧化膜层的耐蚀性和耐磨性均提高,当加压时间间隔150s时耐蚀能力最佳,当加压时间间隔60s时耐磨性最强.

The effects of interval of enhancive voltage on micro-arc oxidation(MAO)coating of magnesium alloy AZ91D were investigated in silicate electrolyte.The microstructures were studied with TT230 digital coating thickness gauge,JSM-6700F scanning electron microscope,2206 surface roughness measuring instrument and W-92 Coating adhesion scratch test machine,and the corrosion and wear resistance were assessed by means of CHI660C electrochemistry workstation and UMT-2MT ball-block reciprocating friction tester.The results show that with the increasing of interval of enhancive voltage,all of the thickness,roughness and bonding force of MAO coating always increase.The porosity of the coatings first increases,then decreases;it is up to its maximum values when interval of enhancive voltage is 150 s.The MAO coatings have the better corrosion and wear resistance than matrix metal,which have the best corrosion resistance as interval of enhancive voltage is 150 s and the best wear resistance as enhancive voltage is 60 s.