LY12铝合金微弧氧化膜的生长过程  

Growth Process of Micro-Arc Oxidation Coating on LY12 Aluminum Alloy

作　　者：国大鹏[1] 孙志华[1] 刘明[1] 郭孟秋[1] 汤智慧[1] 宇波[1] 陆峰[1] 

机构地区：[1]北京航空材料研究院,北京100095

出　　处：《材料保护》2009年第10期10-12,16,共4页Materials Protection

摘　　要：为了进一步了解铝合金微弧氧化膜的生长状况、生长过程和机理,在硅酸盐体系中,采用恒流法对LY12铝合金分别进行了5,10,30,45,75,120 min的微弧氧化处理。采用扫描电镜和电化学阻抗谱对氧化膜进行了分析。结果表明:随着氧化时间的延长,氧化膜明显变得粗糙,膜内孔道被填补;随着膜层厚度的增加,反应后期氧化膜分为内外2层,表层疏松,内层致密;电化学阻抗谱由双容抗形转变为拉长的半圆弧,反应电阻增加,电化学过程由活化过程转变为扩散过程控制,氧化膜对基体的保护性能增强。LY12 Al alloy samples were treatedby micro-arc oxidation ( MAO) in silicate electrolyte for differenttime (5, 10, 30, 45, 75 min, and 120 min).The morphologyand electrochemical performance of the micro-arc oxidation filmwere analyzed by means of scanning electron microscopy ( SEM)and electrochemical impedance spectroscopy (EIS).Results indicate that the pores in the MAO film are filled at an extended oxidation time, the thickness and roughness significantly increasethereat.The MAO film obtained at an extended micro-arc oxidation time was composed of a loose surface layer and a compact inner layer.At the same time, the electrochemical impedance spec-tra of the film was changed from double semicircular capacitivearc to single dreich semicircular capacitive arc, and the reactionresistance was increased thereat.And the electrochemical processdominated by activation process was transformed to that dominatedby diffusion, while the oxidation film had better protection to themetal matrix.

关 键 词：微弧氧化 铝合金 氧化膜 生长过程 形貌 电化学阻抗谱 

分 类 号：TG174.451[金属学及工艺—金属表面处理]