摘要
研究了AZ91D镁合金的钼酸盐化学转化表面处理工艺,利用点滴法和极化曲线法测试转化膜的耐蚀性,用测厚仪测定膜层的厚度,用SEM、EDS和XRD研究转化膜的形貌、成分和结构并探讨了成膜机理。结果表明,当Na2MoO4、NaH2PO4、Ca(NO3)2浓度分别为30 g/L、25 g/L、4 g/L,pH为3,温度为40℃,转化时间为20 min时膜层耐蚀性最好,膜层主要由Mg2Mo3O8组成,自腐蚀电位比空白试样提高了58 mV,对铁红漆的附着力达到了4B级。
The molybdate chemical conversion surface treatment for AZ91D magnesium alloy was investigated.The corrosion resistance of conversion coatings was tested by dropping test and polarization curve methods.The thickness of conversion film to organic coats was tested by thickness gauge.The microstructure,elements,structure and possible conversion mechanism were analyzed by SEM,EDS and XRD.The results show the best conditions are 30 g/L Na2MoO4,25 g/L NaH2PO4,4 g/L Ca（NO3）2,pH=3.0,40 ℃,20 min.The molybdate chemical conversion film is composed of Mg2Mo3O8and its corrosion potential is 58 mV higher than that of the original magnesium alloy.Its adhesive force grade to iron red paint coating is 4B.
出处
《金属热处理》
CAS
CSCD
北大核心
2010年第6期93-98,共6页
Heat Treatment of Metals
基金
南京工程学院科研基金项目(KXJ07009)
江苏省高等学校大学生实践创新训练计划项目(166201090020)
关键词
镁合金
表面处理
化学转化
钼酸盐
magnesium alloy
surface treatment
chemical conversion
molybdate
