Study Of Manufacture Of The Anti-wear And The Ornamental Coating On The Aluminum Alloys By Micro-arc Oxidation

Aluminum alloy is widely applied to engineering due to its outstanding specific strength, electrical conductivity, thermal conductivity, easily forming and making, etc. However, its lower surface hardness and poor corrosion resistance confine its applied range. So, it is important that its engineering properties are improved by surface treatment on aluminum alloy.The color coating on aluminum alloy is an important side of surface treatment. The people have higher requirement about colorful aluminum alloy product. Since 1980s, our country started to study the color coatings on aluminum alloy but there are no huge breakthrough on this technology. The color of coating are still bald. So it is very important to lucubrate the color coating on aluminum alloy to gain the colorful aluminum alloy product.The color coating on aluminum alloy is prepared by traditional technology, which include that film of anodic oxidation adsorb organic or inorganic color dye, and color coatings is directly formed by anode oxidation. But the coating obtained by said two technologies has labile color, lower wearing resistance and poor corrosion resistance, etc. Micro-arc oxidation is also called micro-plasma oxidation or positive spark deposit technology. It is a new surface treatment technique, which is developed from anodic oxidation. It is a technology that ceramic film is formed in condition of hyperthermia and heavy pressure produced by micro-plasma on aluminum alloy in given electrolyte. A film with excellent hardness, heat resistant, corrosion resistance, adhesive power and color can be prepared by said micro-plasma oxidation technology.Confecting different electrolyte and adding different additives into electrolyte can acquire coatings of different colors on LY12 aluminum alloy in this article. The microcosmic configuration, phase distributions and constituents are investigated by X-ray diffract meter. The ceramic coating is mainly composed of γ-Al₂O₃ and α-Al₂O₃ by X-ray diffraction analysis. So it can be conclude that the thickness increasing of coating is caused primarily by means of the combination of aluminum and oxygen, and other elements hardly join in the course. The coatings have different colors because of the different elements of additives. I have analyzed the micro-shape and fabric of ceramic oxide-coating, and...