摘要
利用自行研制的100kW微弧氧化设备对LY12铝合金进行微弧氧化表面处理。采用IM6e电化学工作站测试了负脉冲个数分别为0,2,4,8时,微弧氧化LY12铝合金在5%NaCl溶液中的极化曲线,并对极化曲线的塔费尔斜率分析。研究表明,微弧氧化30min后,陶瓷层厚度由不加负脉冲时的56μm减小到施加8个负脉冲时的31μm。随负脉冲个数增多,陶瓷层的生长时间变短,溶解时间变长,陶瓷层厚度减薄。加载负脉冲可使LY12铝合金微弧氧化陶瓷层的腐蚀电流降为原来的1/10,耐蚀性大幅度增加。负脉冲为4个时制备陶瓷层的腐蚀电流最小,仅为10.3μA,腐蚀速度最低,耐蚀性最好。
LY12 aluminium alloy was surface oxided in a 100 kW micro-arc oxidation installation. IM6E electrochemistry workstation was used to measure steady state I/E recording and Tafel slope of oxide films which were made at 0, 2, 4 and 8 negative pulses in 5 % NaCl solution. The results showed that the thickness of oxide films was decreased by loading negative pulse. The thickness became thinner with increasing the number of negative pulse, for the growth period shortened and dissolve period prolonged. The corrosion current of the oxide films was decreased by 10 times by loading negative pulse. The corrosion resistance of the films increased greatly, relative to that of the untreated sample. During the treatment of micro-arc oxidation , there was an optimal thickness of ceramic layer. When the number of negative pulses was 4, the corrosion current of the film was the least (only 10. 3 μA) , and its corrosion resistance was the best.
出处
《材料保护》
CAS
CSCD
北大核心
2007年第9期17-19,共3页
Materials Protection
关键词
耐蚀性
铝合金
微弧氧化
极化曲线
负脉冲
corrosion resistance
aluminium alloy
micro-arc oxidation
polarization curve
negative pulse