Preparation method for aluminum-silicon alloy micro-arc oxidation film layer

Abstract

The invention discloses a preparation method for an aluminum-silicon alloy micro-arc oxidation film layer. The preparation method for the aluminum-silicon alloy micro-arc oxidation film layer comprises the following steps of S1, pretreatment: removing silicon elements on the surface of an aluminum-silicon alloy substrate; and S2, micro-arc oxidation: placing the aluminum-silicon alloy treated in the step S1 in an alkaline electrolyte for micro-arc oxidation treatment, wherein a constant-voltage micro-arc oxidation mode or a segmented constant-current micro-arc oxidation mode is adopted in themicro-arc oxidation process, and the alkaline electrolyte mainly contains aluminate but contains no silicon elements. According to the scheme provided by the invention, the content of the loose porousmullite phase in the aluminum-silicon alloy micro-arc oxidation film layer is reduced, the structure compactness of the film layer is improved, the section of the film layer is changed in a gradientmode, the purpose of efficiently preparing the micro-arc oxidation ceramic film layer with excellent performance on the surface of the aluminum-silicon alloy is achieved, and the surface-strengthenedaluminum-silicon alloy is obtained.

Description

technical field [0001] The invention relates to the technical field of aluminum-silicon alloy surface treatment, in particular to a method for preparing an aluminum-silicon alloy micro-arc oxidation film layer. Background technique [0002] Aluminum-silicon alloy is a forging and casting alloy mainly composed of aluminum and silicon. It has a small solidification shrinkage rate, good casting performance and low production cost, so it has a wide application prospect in industry. However, due to its unsatisfactory surface properties such as wear resistance, corrosion resistance or heat resistance, it still needs surface treatment to improve its surface performance during application, so as to meet certain higher service conditions. In the existing technology, researchers usually use common surface treatment processes such as anodic oxidation to improve its surface properties. However, because the silicon phase is difficult to oxidize under normal conditions, it is impossible t...

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Problems solved by technology

These mullite impurity phases will be doped in the alumina film layer in a disordered manner, resulting in a decrease in the compactness of the micro-arc oxidation film layer on the entire aluminum-silicon alloy surface, and at the same time leading to a decrease in the hardness and wear resistance of the film layer. , corrosion resistance and other performance decreased significantly

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