Processing method and solution for chemical polishing of zinc alloy

A technology of chemical polishing and treatment methods, applied in the field of metal surface treatment methods and related solutions, can solve the problems of hexavalent chromium being easy to cause cancer and difficult to grasp the treatment time, and achieve the effects of short polishing time, good gloss and smooth surface

Active Publication Date: 2011-11-16
NINGBO INST OF MATERIALS TECH & ENG CHINESE ACADEMY OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, in the surface polishing process of zinc alloys, chromic anhydride is mostly used for treatment, and the processing time is difficult to control, and hexavalent chromium is easy to cause cancer. It is necessary to develop a stable zinc alloy chemical polishing process that does not use hexavalent chromium

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0027] Prepare a chemical polishing solution with the following components:

[0028] Nitric acid 30ml / L

[0029] Phosphoric acid 30ml / L

[0030] Sulfuric acid 30ml / L

[0031] Thiourea 2g / L

[0032] Temperature 40°C

[0033] Take a zinc alloy sample and wash it with water, alkali and ultrasonic cleaning in sequence, and then immerse the sample in the above-mentioned chemical polishing solution for 2 minutes. After taking out the sample, wash it with water and then dry it. The surface of the obtained product is smooth and bright. . If the polishing liquid is polished without adding thiourea, the surface will be corroded locally, with pits and uneven surface.

Embodiment 2

[0035] Prepare a chemical polishing solution with the following components:

[0036] Nitric acid 40ml / L

[0037] Phosphoric acid 40ml / L

[0038] Sulfuric acid 20ml / L

[0039] Thiourea 3g / L

[0040] Temperature 50°C

[0041] Take a zinc alloy sample and wash it with water, alkali and ultrasonic cleaning in sequence, and then immerse the sample in the above chemical polishing solution for 1 minute. After taking out the sample, wash it with water and then dry it. The surface of the obtained product is smooth and bright. . When the polishing liquid does not contain phosphoric acid, the polished surface is not dense and dull.

Embodiment 3

[0043] Prepare a chemical polishing solution with the following components:

[0044] Nitric acid 20ml / L

[0045] Phosphoric acid 50ml / L

[0046] Sulfuric acid 10ml / L

[0047] Thiourea 1g / L

[0048] Temperature 30°C

[0049] Take a zinc alloy sample and wash it with water, alkali and ultrasonic cleaning in sequence, and then immerse the sample in the above chemical polishing solution for 5 minutes. After taking out the sample, wash it with water and then dry it. The surface of the obtained product is smooth and bright. . When the temperature is polished at 60°C, the surface will be uneven and dull.

[0050] In the implementation example, the nitric acid is commonly used in industry with a concentration of 66-68% (volume ratio), phosphoric acid is commonly used in industry with a concentration of 80-90% (volume ratio), preferably 85% (volume ratio), and sulfuric acid is The sulfuric acid commonly used in industry has a concentration of more than 90% (volume ratio), prefera...

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PUM

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Abstract

The invention provides a processing method and solution for the chemical polishing of a zinc alloy. The method comprises the following steps: a, pretreatment, namely degreasing and cleaning a zinc alloy workpiece; b, chemical polishing, namely dipping the degreased and cleaned zinc alloy workpiece into chemical polishing solution; and c, posttreatment, namely performing cleaning and drying treatment after the polishing is finished, wherein the chemical polishing solution takes water as solvent, and mainly comprises nitric acid, phosphonic acid, sulphuric acid and thiourea; the chemical polishing solution is prepared by mixing ordinary acids and organic substances, thus the components are simple and convenient to control, and the polishing effect is good; and the chemical polishing solution can be matched with other chemical treatment links.

Description

technical field [0001] The invention relates to a metal surface treatment method and a related solution, in particular to a zinc alloy surface polishing treatment method and a solution. Background technique [0002] Zinc alloy has low melting point, high specificity, good fluidity, easy fusion welding, brazing and plastic processing, has good mechanical properties and wear resistance at room temperature, and has the advantages of easy recycling and remelting of residual waste. It has been widely used in national defense, electronic appliances, etc. However, in the zinc alloy surface polishing process, most of them use chromic anhydride for treatment, and the processing time is difficult to control and hexavalent chromium is easy to cause cancer. It is necessary to develop a stable zinc alloy chemical polishing process that does not use hexavalent chromium. [0003] The Chinese patent No. 85102657 is "Electropolishing method for the surface of copper-zinc alloy", which belon...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C23F3/06
Inventor 宋振纶沈素峰应华根李建忠
Owner NINGBO INST OF MATERIALS TECH & ENG CHINESE ACADEMY OF SCI
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