TWI477648B - Anticorrosion surface treatment for al and al-alloy and articles treated by same - Google Patents

Description

Aluminum and aluminum alloy surface anticorrosion treatment method and product thereof

The invention relates to an aluminum and aluminum alloy surface anticorrosive treatment method and a product thereof.

Aluminum alloy has the advantages of light weight and good heat dissipation performance, and is widely used in communications, electronics, transportation, construction and aerospace. An aluminum oxide protective film is formed on the surface of the aluminum alloy in the air. Under normal atmospheric conditions, the aluminum oxide film on the surface of the aluminum alloy can effectively protect the aluminum alloy substrate, and in the moisture containing the electrolyte, for example, the surface of the ocean. In the atmospheric environment, the surface of the aluminum alloy is prone to pitting corrosion, which seriously degrades the appearance of the aluminum alloy product and at the same time leads to shortened service life of the product.

Salt spray resistance is an important parameter for the corrosion resistance of aluminum alloy. In order to improve the salt spray resistance of aluminum alloy, it is usually necessary to form a surface film on the surface of aluminum alloy. Common treatment methods include anodizing, baking paint, etc. However, these processes all have large environmental pollution problems. While vacuum coating (PVD) technology is a very environmentally friendly coating process, and can be coated with a wide variety of coatings and excellent wear resistance, the surface of aluminum alloy usually has more small depressions or pores, and the PVD process is deposited. The film layer usually has a contoured structure on the surface of the substrate, and the film layer deposited in the depressions or voids is often thinner than other regions, so the depression or void region in the salt spray test tends to be more susceptible to pitting, resulting in a film layer. It is impossible to effectively prevent the erosion of salt spray, that is, the corrosion resistance is poor.

In view of this, it is necessary to provide an anticorrosive treatment method which can effectively improve the corrosion resistance of aluminum and aluminum alloys.

In addition, it is also necessary to provide an aluminum article obtained by the above method.

An aluminum and aluminum alloy surface anticorrosive treatment method comprises the steps of: providing an aluminum matrix; chemically degreasing the aluminum matrix; preparing a cerium salt doped decane hybrid film on the aluminum substrate by a sol-gel method; The coating method forms a ceramic coating composed of a refractory compound on the cerium salt-doped decane hybrid film.

The aluminum product obtained by the above-mentioned aluminum and aluminum alloy surface anti-corrosion treatment method comprises an aluminum substrate, a cerium salt-doped decane hybrid film formed on the surface of the aluminum substrate, and a refractory formed on the cerium salt-doped decane hybrid film. A ceramic coating consisting of a compound.

The aluminum and aluminum alloy surface anti-corrosion treatment method of the present invention firstly prepares a cerium salt-doped decane hybrid film on an aluminum substrate by a sol-gel method, and then plated on the cerium salt-doped decane hybrid film. Wear-resistant ceramic coating. The cerium salt-doped decane hybrid membrane on the one hand planarizes the surface of the aluminum matrix, and on the other hand, the cerium salt-doped decane hybrid membrane has a compact structure, good barrier property, high chemical stability, and strong binding force with the aluminum matrix. Has a good anti-corrosion function. Combined with the outer wear-resistant ceramic coating, it can protect the yttrium-doped decane hybrid film from mechanical damage. Therefore, the aluminum product has good corrosion resistance.

10‧‧‧Aluminum products

20‧‧‧Aluminum matrix

30‧‧‧铈 salt-doped decane hybrid film

40‧‧‧Ceramic coating

41‧‧‧Alumina oxynitride layer

42‧‧‧Alumina layer

43‧‧‧Aluminum nitride layer

44‧‧‧Chromium oxynitride layer

1 is a schematic view showing the principle of connecting a stainless steel and an alumina ceramic according to a preferred embodiment of the present invention.

2 is a cross-sectional view showing a joint of a stainless steel and an alumina ceramic according to a preferred embodiment of the present invention.

The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

The aluminum and aluminum alloy surface anticorrosive treatment method of the preferred embodiment of the present invention mainly comprises the following steps: providing an aluminum substrate 20, the aluminum matrix material being pure aluminum or aluminum alloy.

The aluminum substrate 20 is chemically degreased. The chemical degreasing is to immerse the aluminum substrate 20 in a degreasing solution at 60-80 ° C for 30-60 s. The deoiling solution used is 25-30 g/L sodium carbonate and 20-25 g/L trisodium phosphate (Na ₃ PO _{4 ).} An aqueous solution of .12H ₂ O) and 1-3 g/L of an emulsifier, wherein the emulsifier is an emulsifier having a trade name of OP-10, the main component of which is a condensate of an alkylphenol and ethylene oxide.

A cerium salt-doped decane hybrid film 30 is prepared on the chemically degreased aluminum substrate 20. In this embodiment, the cerium salt-doped decane hybrid film 30 is prepared by a sol-gel method, as follows: ethyl ortho-nonanoate (TEOS), γ-glycidoxypropyltrimethyl decane (GPTMS), Ethanol, cerium nitrate and water are mixed at a mass ratio of 10-20:30-40:10-20:15-30:2-5, and uniformly stirred to obtain a mixed solution. The pH was adjusted to 3.8-4.2 with acetic acid and sodium acetate. The mixture is sealed and placed in a constant temperature water bath of about 30-60 ° C for 8-12 hours to obtain a decane hybrid sol. Adding 2%-4% of ethylenediaminetetraacetic acid (EDTA) to the total quality of the decane hybrid sol in the hydrolyzed decane hybrid sol After stirring, a film forming solution was obtained. Then, the obtained film forming solution is coated on the aluminum substrate 20 by dipping or smearing, and the coated aluminum substrate 20 is air-dried at room temperature to form a uniform and stable gel layer on the aluminum substrate 20, followed by 120. Curing is carried out at -150 ° C, whereby a dense cerium salt-doped decane hybrid film 30 can be formed on the aluminum substrate. The cerium salt-doped decane hybrid film 30 has a thickness of about 0.1 to 0.4 μm. The mixing ratio of the TEOS, GPTMS, ethanol, cerium nitrate and water is preferably 10:20:10:15:2. The hydrolysis time is preferably 10 hours. The hydrolysis temperature is preferably 40 °C. The curing temperature is preferably 130 °C.

The aluminum substrate 20 on which the cerium salt-doped decane hybrid film 30 is formed is subjected to a vacuum plating treatment to form a ceramic coating layer 40 composed of a refractory compound on the cerium salt-doped decane hybrid film 30. In this embodiment, the ceramic coating 40 includes a layer of aluminum oxynitride 41, a layer of aluminum oxide (Al ₂ O ₃ ) 42 and an aluminum nitride (AlN) layer 43 formed directly on the crucible. On the salt-doped decane hybrid film 30, the aluminum nitride layer 43 is formed on the aluminum oxide layer 42, and the aluminum oxynitride layer 41 is formed on the aluminum nitride layer 43.

Referring to FIG. 2, in another embodiment, the ceramic coating 40 may further include a layer of aluminum oxynitride 41 and a layer of oxynitride chrome 44. The aluminum oxynitride layer 41 is directly formed on the cerium salt-doped decane hybrid film 30, and the oxynitride layer 44 is formed on the aluminum oxynitride layer 41.

The vacuum coating process can adopt an existing vacuum coating method, such as magnetron sputtering or arc ion plating, and the specific process will not be described in detail herein.

Referring to FIG. 1 , an aluminum product 10 obtained by the above-mentioned aluminum and aluminum alloy surface anti-corrosion treatment method comprises an aluminum substrate 20, a cerium salt-doped decane hybrid film 30 formed on the surface of the aluminum substrate 20, and a cerium salt-doped salt formed thereon. A ceramic coating 40 composed of a refractory compound on the heterocycloalkyl hybrid film 30. The cerium salt-doped decane hybrid film 30 is formed by a rare earth cerium salt doped organic decane hybridization film 30, which is mainly composed of five elements of Si, O, C and H, and an atom The number ratio Si:O:C:H=0.1-2:2-3:2-4:2-8. The cerium salt-doped decane hybrid film 30 has a thickness of about 0.1 to 0.4 μm. In this embodiment, the ceramic coating 40 includes a layer of aluminum oxynitride 41, a layer of aluminum oxide (Al ₂ O ₃ ) 42 and an aluminum nitride (AlN) layer 43 formed directly on the crucible. On the salt-doped decane hybrid film 30, the aluminum nitride layer 43 is formed on the aluminum oxide layer 42, and the aluminum oxynitride layer 41 is formed on the aluminum nitride layer 43.

Referring to FIG. 2, in another embodiment, the ceramic coating 40 includes a layer of aluminum oxynitride 41 and a layer of oxynitride chrome 44. The aluminum oxynitride layer 41 is directly formed on the cerium salt-doped decane hybrid film 30, and the oxynitride layer 44 is formed on the aluminum oxynitride layer 41.

The ceramic coating 40 has an overall thickness of between about 2 and about 5 microns.

The aluminum product 10 sample prepared by the anticorrosive treatment method of the present invention was tested at 35 ° C neutral salt spray (NaCl concentration: 5%). As a result, it was found that the aluminum product 10 sample showed corrosion after 72 hours and had good corrosion resistance.

The aluminum and aluminum alloy surface anti-corrosion treatment method of the present invention firstly prepares a cerium salt-doped decane hybrid film 30 on the aluminum substrate 20 by a sol-gel method, and then the cerium salt-doped decane hybrid film. 30 is coated with a wear resistant ceramic coating 40. The cerium salt-doped decane hybrid film 30 planarizes the surface of the aluminum substrate 20 on the one hand, and the cerium salt-doped decane hybrid film 30 has a compact structure, good barrier property, high chemical stability, and aluminum matrix 20 on the other hand. Strong bonding and good anti-corrosion function. Together with the outer wear-resistant ceramic coating 40, the strontium salt-doped decane hybrid film 30 can be protected from mechanical damage. Therefore, the aluminum article 10 is made to have good corrosion resistance.

In summary, the present invention complies with the requirements of the invention patent and submits a patent application according to law. but The above description is only the preferred embodiment of the present invention, and equivalent modifications or variations made by those skilled in the art will be included in the following claims.

10‧‧‧Aluminum products

20‧‧‧Aluminum matrix

30‧‧‧铈 salt-doped decane hybrid film

40‧‧‧Ceramic coating

41‧‧‧Alumina oxynitride layer

42‧‧‧Alumina layer

43‧‧‧Aluminum nitride layer

Claims (10)

An aluminum and aluminum alloy surface anticorrosive treatment method comprises the steps of: providing an aluminum matrix; chemically degreasing the aluminum matrix; preparing a cerium salt doped decane hybrid film on the aluminum substrate by a sol-gel method; The coating method forms a ceramic coating composed of a refractory compound on the cerium salt-doped decane hybrid film. The method for preserving the surface of aluminum and aluminum alloy according to claim 1, wherein the method for preparing the cerium salt-doped decane hybrid film by the sol-gel method comprises: ethyl ortho-nonanoate, γ- Glycidoxypropyltrimethyl decane, ethanol, cerium nitrate and water are mixed at a mass ratio of 10-20:30-40:10-20:15-30:2-5 to obtain a mixed solution; acetic acid and sodium acetate are used; The pH of the mixture is adjusted to 3.8-4.2; the mixture is sealed and then hydrolyzed at 30-60 ° C for 8-12 hours to obtain a decane hybrid sol; a predetermined volume of ethylene diamine is added to the hydrolyzed decane hybrid sol. The tetraacetic acid is obtained as a film forming solution; the film forming solution is coated on the aluminum substrate; the coated aluminum substrate is air-dried at room temperature to form a gel layer on the aluminum substrate; and then cured at 120-150 ° C. The cerium salt-doped decane hybrid film is formed on an aluminum substrate. The method for preserving aluminum and aluminum alloy surface as described in claim 2, wherein the mixture ratio of ethyl ortho-nonanoate, γ-glycidoxypropyltrimethyl decane, ethanol, cerium nitrate and water According to the quality of 10:20:10:15:2. The method for preserving the surface of aluminum and aluminum alloy according to claim 2, wherein the mixture has a hydrolysis temperature of 40 ° C, a hydrolysis time of the mixture of 10 hours, and a curing temperature of 130 ° C. The anti-corrosion treatment method for aluminum and aluminum alloy surface according to claim 1, wherein the antimony salt The doped decane hybrid film is composed of five elements of Si, O, C and H, and the atomic ratio is Si:O:C:H=0.1-2:2-3:2-4:2-8. The method for preserving the surface of aluminum and aluminum alloy according to claim 1, wherein the ceramic coating comprises a layer of aluminum oxynitride, an aluminum oxide layer and a layer of aluminum nitride, the aluminum oxide layer being directly formed on The cerium salt is doped on the cerium hybrid film, and the aluminum nitride layer is formed on the aluminum oxide layer, and the aluminum oxynitride layer is formed on the aluminum nitride layer. The method for preserving the surface of aluminum and aluminum alloy according to claim 1, wherein the ceramic coating comprises a layer of aluminum oxynitride and a layer of chromium oxynitride, and the layer of aluminum oxynitride is directly formed on the strontium salt. On the heterocycloalkyl hybrid film, the chromium oxynitride layer is formed on the aluminum oxynitride layer. The method for preserving the surface of aluminum and aluminum alloy according to claim 1, wherein the chemical degreasing is to immerse the aluminum substrate in a degreasing solution at 60-80 ° C for 30-60 s, and the degreasing solution used is An aqueous solution of 25-30 g/L sodium carbonate, 20-25 g/L trisodium phosphate and 1-3 g/L emulsifier. The method for preserving the surface of aluminum and aluminum alloy according to claim 1, wherein the aluminum substrate is made of pure aluminum or aluminum alloy. An aluminum product prepared by the surface anticorrosive treatment method for aluminum and aluminum alloy according to any one of claims 1-9.