前处理对化学转化处理铝锂合金耐蚀性的影响  

Influence of Pretreatment on Corrosion Resistance of Chromate Conversion Coated Aluminum-lithium Alloy

作　　者：易俊兰 吴松林 刘明辉[2] 赵亮亮[2] 宋袁曾 陈洁 宇波[2] 

机构地区：[1]上海飞机制造有限公司,上海200436 [2]中航工业北京航空材料研究院金属腐蚀与防护研究室,北京100095

出　　处：《表面技术》2013年第1期42-45,共4页Surface Technology

摘　　要：采用手工脱氧、打磨脱氧、浸渍脱氧三种不同的前处理工艺对新型2198铝锂合金进行前处理,之后手工刷涂Alodine1200s化学处理液进行化学转化处理。通过极化曲线和交流阻抗谱,研究了所得试样在3.5%NaCl溶液中的腐蚀行为,并结合微观形貌分析,研究了前处理方式对试样耐蚀性的影响。结果表明:打磨脱氧前处理的试样击穿电位最正,自腐蚀电流密度最低,容抗弧半径最大,阻抗模值最大,低频段阻抗相位角最接近于-90°,耐蚀性最好。Three pretreatments including manual brushing deoxidizing, sanding deoxidizing and dipping deoxidizing were respectively applied on A1-Li alloy 2198. Subsequently, Alodinel200s chromate conversion solution was manually brushed on the samples. The corrosion resistances of the chromate conversion coated samples in 3.5 % NaC1 solution were studied by polarization curve and electrochemical impedance spectroscopy （EIS）, and the influence of the pretreatment on corrosion resistances of the samples was analyzed by scanning electron microscopy （SEM）. The results show that Eb of the sanding deoxidizing sample is the most positive and Jco, of this sample is the lowest. The radius of capacitive are in Nyquist plot and the modulus of corrosion resistance in Bode plot arrive at the maximum because of the sanding deoxidizing pretreatment. Under the same condition, the phase angle of corrosion resistance in the low frequency range is most close to -90°. Therefore, the corrosion resistance of the sanding deoxidizing sample is the best.

关 键 词：铝锂合金 前处理 铬酸盐化学转化膜 交流阻抗谱 极化曲线 耐蚀性 

分 类 号：TG174.451[金属学及工艺—金属表面处理]