Key Laboratory of Superlight Materials & Surface Technology, Ministry of Education, Harbin Engineering University, Harbin 150001, P. R. China.
ACS Appl Mater Interfaces. 2011 Sep;3(9):3682-90. doi: 10.1021/am200863s. Epub 2011 Aug 24.
Superlight Mg-Li alloy is a promising structural materials in aerospace, automobile, and electronics because of its excellent properties such as low density, high ductility, superior strength-to-weight ratio, and good damping ability. The fabrication of compact plasma electrolytic oxidation coatings with excellent corrosion resistance is valuable for the widespread application of Mg-Li alloy. Here we present a ceramic coating on the surface of Mg-14Li-1Al (LA141) alloy for corrosion protection via plasma electrolytic oxidation (PEO) in an alkaline silicate electrolyte with tungstate as an additive. X-ray photoelectron spectroscopy and thin film-X-ray diffraction analysis of coatings show that the surface coating is mainly comprised of Mg(2)SiO(4), MgO and WO(3). Scanning electron microscopy observations have revealed that the dense and compact coating formed in the presence of tungstate has less structural imperfections in comparison to the control one fabricated without use of tungstate. The effect of oxidation time on the morphology and phase composition of coatings is also examined in detail.
超轻 Mg-Li 合金因其低密度、高延展性、优异的强度-重量比和良好的阻尼能力等优良性能，在航空航天、汽车和电子等领域是一种很有前途的结构材料。制备具有优异耐腐蚀性的致密等离子电解氧化涂层对于广泛应用 Mg-Li 合金具有重要价值。本文采用碱性硅酸钠电解液中添加钨酸盐的方法，通过等离子电解氧化（PEO）在 Mg-14Li-1Al（LA141）合金表面制备陶瓷涂层，以实现对其的腐蚀防护。通过 X 射线光电子能谱和薄膜 X 射线衍射分析表明，涂层的主要成分是 Mg(2)SiO(4)、MgO 和 WO(3)。扫描电子显微镜观察发现，与未添加钨酸盐制备的涂层相比，在添加钨酸盐的情况下形成的致密、紧凑的涂层具有较少的结构缺陷。还详细研究了氧化时间对涂层形貌和相组成的影响。
