CAJ | 학술논문

开发一种环境友好的方法合成碳钠铝石转化膜以提高AZ31镁合金的耐蚀性.该膜由两步法制得:首先将AZ31合金浸泡在一直通CO2气体的Al2(SO4)3溶液中,获得前躯体膜;随后将该前躯体膜浸泡在溶有Al的Na2CO3溶液中以获得碳钠铝石膜.通过环境扣描电镜观察转化膜的表面形貌,并利用EDS能谱和X射线衍射分析其化学成分.采用电化学和浸泡实验来评价该转化膜对AZ31合金的防护作用.结果表明:膜的表面存在网状裂痕,其成分主要为碳钠铝石NaAlCO3(OH)2、Al(OH)3和Al5(OH)<,13>(CO3)·5H3O.该膜能提高Mg基体的自腐蚀电位,并减少其腐蚀电流密度.浸泡实验后,除了局部小区域有个别点蚀坑外,膜基本保持完整;而基体却腐蚀严重.说明碳钠铝石转化膜能很好地保护镁合金.
개발일충배경우호적방법합성탄납려석전화막이제고AZ31미합금적내식성.해막유량보법제득:수선장AZ31합금침포재일직통CO2기체적Al2(SO4)3용액중,획득전구체막;수후장해전구체막침포재용유Al적Na2CO3용액중이획득탄납려석막.통과배경구묘전경관찰전화막적표면형모,병이용EDS능보화X사선연사분석기화학성분.채용전화학화침포실험래평개해전화막대AZ31합금적방호작용.결과표명:막적표면존재망상렬흔,기성분주요위탄납려석NaAlCO3(OH)2、Al(OH)3화Al5(OH)<,13>(CO3)·5H3O.해막능제고Mg기체적자부식전위,병감소기부식전류밀도.침포실험후,제료국부소구역유개별점식갱외,막기본보지완정;이기체각부식엄중.설명탄납려석전화막능흔호지보호미합금.
An environmentally friendly method for synthesizing a dawsonite conversion film was developed to improve the corrosion resistance of AZ31 Mg alloy. The film was prepared by two steps: the AZ31 alloy was first immersed in an A12(504)3 solution venting CO2 gas to form a precursor film, and then the precursor film was treated in a Na2CO3 solution dissolved with Al to obtain the dawsonite film. The surface morphology of the conversion film was observed with an environmental scanning electronic microscope. The chemical composition of the conversion film was analyzed by energy dispersive X-ray spectroscopy and X-ray diffractometry. Electrochemical and immersion tests were carried out to evaluate the protection effect of the conversion film on AZ31 alloy. There are some network-like cracks on the surface of the film. The conversion film is mainly composed of dawsonite density of the Mg substrate. After immersion tests, the film almost keeps intact, except for the localized narrow areas with several corrosion pits, while the bare material undergoes serious general corrosion. It is indicated that the dawsonite film can provide good protection to the magnesium alloy.