摘要
为了提高铜及其合金的耐蚀性能,研究了一种含硝酸镧的新型钝化工艺,处理后的铜合金表面形成了金黄色的稀土钝化膜。采用硝酸点滴、湿热试验及盐雾试验等方法对钝化膜的耐蚀性进行了表征。结果表明,最佳钝化工艺为:23 g/L有机羧酸,16 g/L苯并三氮唑(BTA),4 g/L硝酸镧,1 g/L促进剂,温度60℃,钝化时间3 min。稀土盐的加入使其耐硝酸点滴及湿热试验的时间均延长了3倍多;在5%NaCl溶液的腐蚀速率降低6倍,在扫描电镜下可以明显观察到加入稀土盐后合金表面结构变得均匀致密;电子探针分析表明,稀土钝化膜的La,O等元素都均匀分布在膜层表面。
A passivation solution containing lanthanum nitrate was developed to improve the corrosion resistance of copper and its alloy.The corrosion resistance of the passivation coatings was evaluated using dropping nitric acid test,moisture-heat test,and salt-spray test.The microstructure and elemental composition of the passivation coatings were analyzed by means of scanning electron microscopy and electron probe microanalysis.Results indicated that a yellow chemical passivation coating was obtained on the surface of copper alloys.The rare earth conversion coating was capable of increasing the resistant duration of the substrate in dropping nitric acid test and moisture-heat test by a factor of 3,and the corrosion rate of the copper alloys was reduced to 1/6 in aqueous solution of 5% NaCl.The conversion coating formed on the substrate surface was uniform and compact,and La and O were uniformly distributed in the conversion coating.
出处
《材料保护》
CAS
CSCD
北大核心
2008年第8期35-37,共3页
Materials Protection
关键词
铜合金
钝化工艺
硝酸镧
耐蚀性能
copper alloys
passivation process
lanthanum nitrate
corrosion resistance
