A kind of ash remover after sealing of aluminum alloy anodic oxidation process and preparation method thereof

Abstract

The invention relates to an ash removal agent applied after closing of an aluminum alloy anodizing technology and a preparation method thereof. The ash removal agent is applied after the closing of the aluminum alloy anodizing; the ash removal agent is prepared from the following components in parts by weight: 50-200 parts of sulfuric acid, 2-100 parts of hexavalent iron salt, 5-50 parts of trivalent iron salt, 10-50 parts of hydrogen peroxide and 5-50 parts of a corrosion inhibitor. The ash removal agent applied after closing of the aluminum alloy anodizing technology is applied for ash removal in the neutralizing treatment process after aluminum alloy pretreatment, and the ash removal is fast and environmentally friendly; moreover, the aluminum alloy is soaked to remove ash, and the ashremoval can totally act on each position of the aluminum alloy without leaving dead angle or residue; toxic or harmful gases are not generated during the ash removal; without hexavalent chromium, theash removal agent does not pose a threat to the health of operators; the preparation technology of the ash removal agent is simple, efficient, energy-saving and environmentally friendly.

Description

technical field [0001] The invention relates to the field of surface treatment of aluminum alloys, in particular to an ash remover after sealing of anodic oxidation process of aluminum alloys and a preparation method thereof. Background technique [0002] Aluminum alloy anodic oxidation process, it is easy to produce the phenomenon of hanging ash; however, the layer of ash hanging on the surface of the workpiece, due to the complex composition, the mechanism is quite complicated; after the aluminum alloy is etched by alkali, the insoluble in alkali washing Manganese, copper, iron and other alloying elements and their inter-alloy chemicals in the liquid will take the opportunity to form a layer of taupe or gray hanging ash on the surface; in the chemical polishing process, aluminum alloys also have heavy metals, or in order to improve the polishing effect, usually A small amount of heavy metal salt will be added to the polishing solution, and these heavy metal ions will under...

AI Technical Summary

Problems solved by technology

[0002] Aluminum alloy anodic oxidation process, it is easy to produce the phenomenon of hanging ash; however, the layer of ash hanging on the surface of the workpiece, due to the complex composition, the mechanism is quite complicated; after the aluminum alloy is etched by alkali, the insoluble in alkali washing Manganese, copper, iron and other alloying elements and their inter-alloy chemicals in the liquid will take the opportunity to form a layer of taupe or gray hanging ash on the surface; in the chemical polishing process, aluminum alloys also have heavy metals, or in order to improve the polishing effect, usually A small amount of heavy metal salt will be added to the polishing solution, and these heavy metal ions will undergo a substitution reaction with aluminum to form heavy metal particles that are deposited on the surface of the aluminum alloy, and form hanging ash together with the components in the aluminum alloy that are insoluble in the polishing solution; aluminum alloy anode The ash produced by oxidation generally has the following situations: 1. The ash caused by poor treatment before anodic oxidation. In the pore link, complex substances are formed, which are difficult to remove; 2. Dye ash, due to the large amount of impurity components in the anode dye, or insufficient dissolution, the dye particles are adsorbed outside the pores of the anodic oxide film; 3. The ash caused by poor sealing, commonly known as "White mist", this kind of ash will come back after being wiped; 4. The ash caused by over-sealing, usually some white powdery ash, is due to the excessive deposition of nickel salt on the surface, and the appearance is velvety. Water spots or foam marks are caused by poor surfactants

In short, the ash produced by the aluminum alloy anodizing process has complex components and complex principles, and it is difficult to remove after sealing, which has always been a very headache in the industry

[0003] Once the sealed ash is produced, the appearance of the aluminum alloy is very ugly and difficult to handle. It is generally wiped with a damp cloth, and it is difficult to clean the grooves, which consumes a lot of labor and time.

Moreover, the existing ash removal processes are mainly divided into sulfuric acid method and nitric acid method. The sulfuric acid method has the advantages of low cost and good economic benefits. The dissolution rate of the hanging ash produced and the elemental copper precipitated on the surface after chemical polishing is slow or even powerless. Moreover, the sulfuric acid method takes a long time to operate, and snowflake-like corrosion spots are prone to appear after ash removal; the nitric acid method is comparable to the sulfuric acid method. Compared with nitric acid, which is an oxidizing acid, it has a strong solubility for hanging ash, and can remove almost all kinds of hanging ash, so that the aluminum can obtain a clean, bright and uniform passivation surface, and avoid the generation of snowflake-like spots, but the nitric acid solution The volatilized nitric acid vapor and its decomposition products not only pollute the air, deteriorate the operating environment of the workshop, but also corrode the workshop and mechanical equipment, causing potential safety hazards, and in actual production, CrO is often added to sulfuric acid or nitric acid 3 , in order to achieve the purpose of enhancing the effect, but hexavalent chromium is a strong carcinogen, in order to protect the health of operators and the environment, it should be avoided

Images