Corrosion-contamination resistant chemical conversion agent and method for preparing chromium-free chemical conversion film

Abstract

The invention relates to the field of aluminum alloy decoration and protection coating for ships, in particular relates to an environmentally-friendly corrosion-contamination resistant chemical conversion agent and application thereof in a chromium-free chemical conversion film, and solves the problems of poor corrosion resistance, high cost, difficulty in large-area construction and the like in the prior art. The chemical conversion agent comprises a component A and a component B. The method for preparing a chemical conversion film comprises the following steps of: forming a first inorganic chemical conversion film layer by the component A and forming an organic contamination resistant closed film by the component B. The component A is a water solution prepared from a main salt, a film-forming accelerator, a buffering agent, a surfactant and the like, and the component B is prepared from silicate, silane, a silica sol, titanate, zirconate, waterborne resins and the like. The chemicalconversion agent does not contain chromium ions and phosphates, and the chromium-free chemical conversion film prepared from the chemical conversion agent has excellent corrosion resistance and contamination resistance, can be used for construction of large-area aluminum alloy sections, and can be used as surface decoration and protection coatings for 5xxx and 6xxx series aluminum alloys.

Description

technical field [0001] The invention relates to the field of marine aluminum alloy decoration and protective coatings, in particular to an environment-friendly anti-corrosion and anti-pollution chemical conversion agent and its application in composite chrome-free chemical conversion coatings. The method is practical and convenient, and the formed chromium-free chemical conversion film has excellent corrosion resistance and stain resistance, and can be used for the construction of large-area aluminum alloy profiles. Background technique [0002] 5xxx and 6xxx aluminum alloys have been widely used in ship structural materials in recent years due to their good corrosion resistance, weldability and mechanical properties. Since the oxide film formed spontaneously by aluminum alloy is relatively thin, it cannot meet the requirements of use in harsh environments such as oceans. Due to the erosion of seawater and hot and humid marine atmosphere, the exposed aluminum alloy surface ...

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Problems solved by technology

[0003] The purpose of the present invention is to provide a corrosion-resistant, anti-staining chromium-free chemical conversion agent and its application in chromium-free chemic

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