LC9Aluminum Alloy Micro-arc Oxidation Ceramic Membrane Growth And Corrosion Resistant

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.