CN112708889A

CN112708889A - Polishing agent containing lanthanum, aluminum workpiece and polishing treatment method thereof

Info

Publication number: CN112708889A
Application number: CN202011458219.8A
Authority: CN
Inventors: 王饶玲
Original assignee: Shenzhen Hengzhaozhi Technology Co Ltd
Current assignee: Shenzhen Hengzhaozhi Technology Co Ltd
Priority date: 2020-12-11
Filing date: 2020-12-11
Publication date: 2021-04-27

Abstract

The invention relates to a polishing agent containing lanthanum, an aluminum workpiece and a polishing treatment method thereof. The lanthanum-containing polishing agent is used for surface pretreatment of an aluminum workpiece and comprises the following components in parts by weight based on 100 parts by weight: 3-10 parts of nitric acid, 0.005-0.02 part of lanthanum sulfate, 5-10 parts of acetic acid, 20-50 parts of phosphoric acid, 5-12 parts of aluminum phosphate, 0.5-3 parts of silver nitrate and the balance of water. After the polishing agent is used for treating, the surface of the aluminum workpiece is clean and bright, and the whole polishing treatment method has the advantages of simple process equipment, capability of treating workpieces with complex shapes, convenience in operation and low use cost.

Description

Polishing agent containing lanthanum, aluminum workpiece and polishing treatment method thereof

Technical Field

The invention relates to the technical field of iron surface treatment, in particular to a polishing agent containing lanthanum, an aluminum workpiece and a polishing treatment method thereof.

Background

In order to improve the surface properties or appearance of the product, the surface of the workpiece is usually treated. For example, surface treatment processes for stainless steel, zinc alloys, aluminum, and the like, and alloys thereof, are in great popularity. Furthermore, most workpieces are also subjected to a pretreatment, such as cleaning, desmutting, or degreasing, prior to surface treatment, and some metal workpieces are also subjected to a polishing treatment.

In general, in the mechanical processing and electronic and electrical industries, the cleaning and polishing treatment, i.e., polishing treatment, of aluminum and aluminum alloy is common. Conventional polishing agents typically employ mechanical polishing or triacid polishing, wherein mechanical polishing is poor for complex workpiece geometries and is prone to cracking and scratching. The triacid in the triacid polishing, namely concentrated nitric acid, concentrated sulfuric acid and concentrated phosphoric acid, reacts violently under the high-temperature condition, gas is volatilized greatly, and a large amount of NO can be generated_XGas is unsafe, has great harm to the environment and large energy consumption.

Disclosure of Invention

In view of the above, a polishing agent containing lanthanum, which has better physical appearance, higher mechanical properties, better corrosion resistance, easy cleaning, special effect, less odor and less energy consumption, a polishing method for aluminum workpieces, and an aluminum workpiece prepared by polishing, are provided.

A polishing agent containing lanthanum comprises the following components in parts by weight based on 100 parts by weight: 3-10 parts of nitric acid, 0.005-0.02 part of lanthanum sulfate, 5-10 parts of acetic acid, 20-50 parts of phosphoric acid, 5-12 parts of aluminum phosphate, 0.5-3 parts of silver nitrate and the balance of water.

A polishing treatment method for an aluminum workpiece comprises the following steps: formulating a polishing agent comprising lanthanum as described above; and (3) immersing the aluminum workpiece into the polishing agent solution, and washing the aluminum workpiece with water after the treatment at the preset time and temperature.

And an aluminum workpiece, the surface of which is polished by the aluminum workpiece polishing treatment method as described above.

After the lanthanum-containing polishing agent is used for treatment, the surface of the aluminum workpiece has high light reflectivity and no defects of pitting corrosion, spots, white mist and the like, and the whole polishing treatment method has the advantages of simple process, small smell, convenience in operation and low use cost.

Detailed Description

The present invention will be described in detail with reference to specific examples.

The embodiment of the invention provides a polishing agent containing lanthanum, which is used for pretreatment of the surface of an aluminum workpiece and comprises the following components in parts by weight based on 100 parts by weight: 3-10 parts of nitric acid, 0.005-0.02 part of lanthanum sulfate, 5-10 parts of acetic acid, 20-50 parts of phosphoric acid, 5-12 parts of aluminum phosphate, 0.5-3 parts of silver nitrate and the balance of water.

Specifically, the weight part of the nitric acid is preferably 5 to 8 parts. The weight portion of the lanthanum sulfate is preferably 0.01-0.02 part, the weight portion of the acetic acid is preferably 6-8 parts, and the weight portion of the phosphoric acid is preferably 30-50 parts. The weight part of the aluminum phosphate is preferably 6-10 parts, and the weight part of the silver nitrate is preferably 1-2 parts. Wherein, the nitric acid is a nitric acid solution with the mass percent of 68%, the acetic acid is an acetic acid solution with the mass percent of 99.5%, and the phosphoric acid is a phosphoric acid solution with the mass percent of 85%. Although the raw materials of the various acids are concentrated acid solutions, the raw materials become dilute acids after being prepared into polishing solutions.

In the chemical etching process, the microscopic projections on the metal surface are in solution and the dissolution rate is much greater than that of the microscopic depressions, resulting in a gradually leveled and smooth, shiny surface. The proportion of each component is controlled to be balanced, so that a better polishing effect is achieved. Nitric acid, acetic acid and phosphoric acid remove oxide skins and enable the surface of aluminum to react quickly, the nitric acid increases oxidability so that the reaction is accelerated, aluminum phosphate increases the viscosity of the solution, the diffusion speed of the aluminum phosphate at the microcosmic projection of the workpiece is much higher than that of the microcosmic recess, and therefore the reaction speed of the microcosmic recess is reduced, and the effect of leveling the surface is achieved. Silver nitrate can effectively avoid the difficulty in reaction due to excessive aluminum phosphate. Lanthanum sulfate can improve the reflectivity of the aluminum alloy.

The embodiment of the invention also provides an aluminum workpiece polishing treatment method, which comprises the following steps: formulating a polishing agent comprising lanthanum as described above; and (3) immersing the aluminum workpiece into a polishing agent solution, performing treatment for a preset time, washing the aluminum workpiece with water, and drying.

Specifically, the predetermined time is 0.5 to 3 minutes. Further, after polishing, passivation or oxidation is performed, and then washing and drying are performed. During polishing treatment, the temperature is controlled at 60-100 ℃. Furthermore, pretreatment such as degreasing, degreasing and descaling is performed before polishing.

The embodiment of the invention also provides the aluminum workpiece, which is polished by the polishing method of the aluminum workpiece, so that the aluminum workpiece forms a clean and bright surface. After the lanthanum-containing polishing agent is used for treatment, the surface of an aluminum workpiece is clean, the light reflectivity is high, and the whole polishing treatment method is simple in process, convenient to operate and low in use cost.

Specifically, the following examples are given in the following examples of Al-Mg alloys with 99.99 mass% aluminum, since the composition of aluminum alloys greatly affects the surface brightness after chemical polishing, and generally, the higher the purity of aluminum, the better the polishing brightness

Example 1

The following components are mixed according to the following parts by weight (the total weight is 100 parts by weight): 3 parts of nitric acid, 0.005 part of lanthanum sulfate, 5 parts of acetic acid, 20 parts of phosphoric acid, 5 parts of aluminum phosphate, 0.5 part of silver nitrate and the balance of water.

The treatment method comprises the following steps: preparing a polishing agent containing lanthanum; deoiling and descaling an aluminum workpiece in advance, then washing with water, immersing the workpiece with a clean surface into a polishing agent solution at 85 ℃, washing with water after 3 minutes, and drying.

After the polishing agent solution is used for processing, the surface of a workpiece is observed, and the whole surface is clean and bright and has consistent color and no abnormity such as spots, white fog, pitting corrosion and the like. The specular reflectivity is more than 40%.

Example 2

The following components are mixed according to the following parts by weight (the total weight is 100 parts by weight): 5 parts of nitric acid, 0.01 part of lanthanum sulfate, 7 parts of acetic acid, 30 parts of phosphoric acid, 7 parts of aluminum phosphate, 1 part of silver nitrate and the balance of water.

The treatment method comprises the following steps: preparing a polishing agent containing lanthanum; deoiling and descaling an aluminum workpiece in advance, then washing with water, immersing the workpiece with a clean surface into a polishing agent solution at 85 ℃, washing with water after 2 minutes, and drying.

After the polishing agent solution is used for processing, the surface of a workpiece is observed, and the whole surface is clean and bright and has consistent color and no abnormity such as spots, white fog, pitting corrosion and the like. The specular reflectivity is more than 50%.

Example 3

The following components are mixed according to the following parts by weight (the total weight is 100 parts by weight): 8 parts of nitric acid, 0.015 part of lanthanum sulfate, 8 parts of acetic acid, 40 parts of phosphoric acid, 10 parts of aluminum phosphate, 2 parts of silver nitrate and the balance of water.

After the polishing agent solution is used for processing, the surface of a workpiece is observed, and the whole surface is clean and bright and has consistent color and no abnormity such as spots, white fog, pitting corrosion and the like. The specular reflectivity is more than 60%.

Example 4

The following components are mixed according to the following parts by weight (the total weight is 100 parts by weight): 10 parts of nitric acid, 0.02 part of lanthanum sulfate, 10 parts of acetic acid, 50 parts of phosphoric acid, 12 parts of aluminum phosphate, 3 parts of silver nitrate and the balance of water.

The treatment method comprises the following steps: preparing a polishing agent containing lanthanum; deoiling and descaling an aluminum workpiece in advance, then washing with water, immersing the workpiece with a clean surface into a polishing agent solution at 85 ℃, washing with water after 1.5 minutes, and drying.

After the polishing agent solution is used for processing, the surface of a workpiece is observed, and the whole surface is clean and bright and has consistent color and no abnormity such as spots, white fog, pitting corrosion and the like. The specular reflectivity is more than 80%.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and other changes and modifications can be made by those skilled in the art according to the spirit of the present invention, and these changes and modifications made according to the spirit of the present invention should be included in the scope of the present invention as claimed.

Claims

1. The polishing agent containing lanthanum is characterized by comprising the following components in parts by weight based on 100 parts by weight: 3-10 parts of nitric acid, 0.005-0.02 part of lanthanum sulfate, 5-10 parts of acetic acid, 20-50 parts of phosphoric acid, 5-12 parts of aluminum phosphate, 0.5-3 parts of silver nitrate and the balance of water.

2. The lanthanum containing polishing agent of claim 1 wherein the nitric acid is present in an amount of 5 to 8 parts by weight.

3. The lanthanum containing polishing agent of claim 1 wherein the lanthanum sulfate is present in an amount of 0.01 to 0.02 parts by weight.

4. The lanthanum containing polishing agent of claim 1 wherein the weight fraction of acetic acid is 6 to 8 parts.

5. The lanthanum containing polishing agent of claim 1 wherein the phosphoric acid is present in an amount of 30 to 50 parts by weight.

6. The lanthanum containing polishing agent of claim 1 wherein the aluminum phosphate is present in an amount of 6 to 10 parts by weight.

7. The lanthanum containing polishing agent of claim 1 wherein the silver nitrate is present in an amount of from 1 to 2 parts by weight.

8. A polishing treatment method for an aluminum workpiece comprises the following steps: formulating a lanthanum containing polishing agent according to any one of claims 1 to 7; and (3) immersing the aluminum workpiece into a polishing agent solution, performing treatment at preset time and temperature, washing the aluminum workpiece with water, and entering the next procedure.

9. The method for polishing an aluminum workpiece according to claim 1, wherein the polishing is carried out after a predetermined time of 0.5 to 3 minutes at a predetermined temperature of 60 to 100 ℃, followed by passivation and then water washing and drying.

10. An aluminum workpiece, characterized in that the surface of the aluminum workpiece is polished by the aluminum workpiece polishing treatment method as set forth in claim 8.