【摘要】 采用恒定小电流密度工艺于硅酸盐体系中在AZ91D镁合金表面制备微弧氧化膜。采用数字式涂层测厚仪、扫描电子镜、表面粗糙度测量仪和涂层附着力划痕试验机等研究其微观结构,利用电化学工作站和球-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:随着氧化时间的延长,阳极电压趋于稳定;氧化膜层的厚度和粗糙随之增大;氧化膜层的结合力、孔隙率则先增大后减小,都在60 min时出现最大值;膜层表面熔融物颗粒尺寸增大,大孔洞的数目随之增多,且分布变得不均匀;氧化时间为40 min时制备的膜层耐蚀能力最强并具有良好的耐磨性。更多还原

【Abstract】 Micro-arc oxidation(MAO) coatings were formed on AZ91D alloy surface by invariable small current density process in silicate electrolyte.The microstructures were studied by digital coating thickness gauge,SEM,surface roughness measuring instrument and coating adhesion scratch test machine,and the corrosion and wear resistance were assessed by electrochemistry workstation and ball-block reciprocating friction tester.The results indicate that with the increase of the oxidation time,the anode voltages are stabilized,the thickness and roughness are always increased.The porosity and bonding force of the MAO coating first increase,and then decrease,they are all reach their maximum values at 60 min.The melting particles of surface are bigger and the number of large holes is increased,and the distribution becomes uneven.The coating has good corrosion resistance and the best wear resistance when the oxidation time is 40 min.更多还原