Papers by Keyword: Micro-Arc Oxidization

Abstract: LY12 aluminum alloy samples were treated by microarc oxidation in sodium metasilicate electrolytes. The effects of treatment time on cell violate and ceramic coating thickness were investigated. The results indicate that the micro-arc oxidization process was divided into two stages, at the first stage, the cell voltage increased linearly at a very high rate of 70 V/min, at the second stage, in the range of 430-470 V, the cell voltage reached a relative stable value. The thickness of the coating increased linearly at the whole stage with increasing treating time. XRD analyses indicate that the ceramic coatings fabricated on the surface of aluminum alloys by micro-arc oxidization are composed of Al phase Al2O3 phase. SEM show that the maximum porosity of the ceramic coatings with distributing uniformly pore diameter are decreased with the increasing treatment time.

Abstract: LY12 aluminum alloy samples were treated by micro-arc oxidation in sodium metasilicate electrolytes with graphite powder. The effects of graphite concentration on thickness, roughness, friction coefficient and phase composite of ceramic coating were investigated. The results indicated that the roughness and friction coefficient of ceramic coatings increased linearly. However, the thickness decreased adding graphite powder. XRD analyses indicated that the ceramic coatings fabricated on the surface of aluminum alloys by micro-arc oxidization were composed of graphite phase. SEM showed that the porosity of the ceramic coatings with distributing nonuniform micropore diameter were inceased with the increasing graphite concentration.