【作者】 张剑；

【导师】 许林； 吴振东；

【作者基本信息】 东北师范大学 ， 无机化学， 2014， 硕士

【摘要】 随着科技的发展和社会的进步,铝合金的应用领域更加广泛。但铝合金耐腐蚀性能较差,限制了铝合金的应用。为了研究和提高其耐腐蚀能力,采用微弧氧化方法分别在铝酸钠和硅酸钠电解液体系下LC9铝合金表面原位生长陶瓷膜,分析膜层形貌和组成,通过电偶腐蚀和快速电化学测试方法评价膜层的耐腐蚀性。利用X-射线衍射仪(XRD)、扫描电子显微镜(SEM)研究膜层相组成和形貌。铝酸盐体系下陶瓷膜层由γ-Al2O3和α-Al2O3相组成,氧化时间越长,α-Al2O3衍射峰越明显。硅铝酸盐体系下陶瓷膜层由γ-Al2O3相组成。铝酸盐体系下陶瓷膜形貌随时间影响较明显,氧化时间短,膜层表面致密性较差,硅酸盐体系陶瓷膜形貌随浓度影响较明显,浓度越大,孔洞减少。电偶腐蚀研究表明,陶瓷膜层分别与铜、铁和LY12接触腐蚀,在铝酸盐和硅酸盐体系下,在接触面积为4cm2条件下,膜层与LY12的偶接电流变化趋势最小,腐蚀电流稳定在30mA,腐蚀速率最小,耐腐蚀性最强。膜层与铁接触,在硅酸盐体系的偶接电流比铝酸盐体系增加4倍。膜层与铜接触偶接电流变化不明显。加速电化学测试表明,铝酸钠体系下时间为50min的膜层,腐蚀电流值为4.05×10-66A/cm2,耐腐蚀性最好。硅酸钠体系下,电流密度为6A/dm2的膜层,腐蚀电流值为1.16×10-6A/cm2,耐腐蚀性最好。膜层的耐腐蚀性整体强于铝合金基体,明显提高了基体的耐腐蚀性。通过接触腐蚀和电化学腐蚀方法评价LC9铝合金陶瓷膜层的耐腐蚀性能。更多还原

【Abstract】 With the development of science and technology and the progress of the society, the application field of aluminum alloy is more widely. But the aluminum alloy corrosion, the application of aluminium alloy limited. In order to study and improve the corrosion resistance of micro arc oxidation method, respectively in the sodium aluminate and sodium silicate electrolyte system under the surface of aluminum alloy LC9in situ growth of ceramic membrane, the surface morphology and composition analysis, the test method of galvanic corrosion and electrochemical corrosion resistance of film.By using X-ray diffraction (XRD), scanning electron microscopy (SEM) on the phase composition and morphology.Ceramic coatings aluminate system by Al2O3gamma and alpha A12O3phase, longer oxidation time, alpha Al2O3diffraction peak more obvious. Ceramic coating silicon aluminate system by γ-A12O3phase compositionMorphology of ceramic membrane aluminate system with obvious effect, oxidation time is short, the film surface is poor, silicate ceramic membrane morphology as a function of concentration effect is obvious, the higher concentration, reduce pores.Galvanic corrosion of ceramic coatings show, respectively with copper, iron and LY12contact corrosion, in aluminate and silicate system, in the contact area under the condition of4cm2film and LY12, coupled with current trends to the minimum, the corrosion current stable at30mA, the lowest corrosion rate, corrosion resistance, the strongest. The film contact with iron, welding current in silicate system I is4times greater than that of aluminate system. The film and the copper contact coupled current does not change obviouslyIndicates that the accelerated electrochemical test, sodium aluminate system for50min film, the corrosion current value is4.05×10-66A/cm2, the corrosion resistance is the best. Sodium silicate system, current density of layer6A/dm2, the corrosion current value is1.16×10-6A/cm2, the corrosion resistance is the best. The corrosion resistance of the whole film in the aluminum alloy matrix, significantly improve the corrosion resistance of the matrix. Through the contact corrosion and electrochemical corrosion evaluation method of LC9aluminum alloy ceramic coating corrosion resistance.更多还原