Aluminium alloy trivalent chromium passivation solution as well as preparation method and passivation technology thereof

A technology of passivation solution and trivalent chromium, which is applied in the coating process of metal materials, etc., can solve the problems of improving corrosion resistance and reducing costs, and achieves the effects of reducing production costs, reducing prices, and light weight

Active Publication Date: 2015-03-04
翊鹏(湖北)实业有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0009] In order to solve the problem that the corrosion resistance of the existing trivalent chromium passivation solution needs to be further improved and the cost needs to be reduced, the present invention proposes an aluminum alloy trivalent chromium passivation solution with better corrosion resistance and lower cost and its preparation method And the passivation process using the passivation solution

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  • Aluminium alloy trivalent chromium passivation solution as well as preparation method and passivation technology thereof

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preparation example Construction

[0038] The preparation method of aluminum alloy trivalent chromium passivation solution of the present invention is as follows:

[0039] The raw materials required for configuration are all from commercially available products. Weigh the chromium nitrate raw material according to the proportion, add appropriate amount of water to dissolve, then add the first group of complexing agent organic acid, stir to dissolve, then add the second group of complexing agent polyhydric alcohol, stir to dissolve , add water to a certain concentration, heat the solution to 50~70°C and keep it warm for 2 hours, then add the film-forming accelerator, stir to dissolve, and get the passivation solution after standing still.

[0040] The passivation process flow using passivator of the present invention is as follows:

[0041] Degreasing (degreasing) - hot water washing (two flows) - activation - water washing (two processes) - passivation - water washing - hot water washing - drying.

[0042] In ...

Embodiment 1

[0049] Prepare passivation solution:

[0050] Select chromium nitrate as the main film-forming salt, first dissolve chromium nitrate at a concentration of 6 g / L with an appropriate amount of water, then add 4 g / L of malic acid, stir to dissolve, then add 4 g / L of glycerol, stir to dissolve, Heat the solution to 50°C and keep it warm for 2 hours, then add nickel nitrate 3 g / L and stir to dissolve, and then passivation solution is obtained after standing still.

[0051] Passivation process:

[0052] Degrease the passivated workpiece, wash with 20 g / L sodium silicate and 3 mL / L OP-10 emulsifier at a temperature of 50°C; use 10 mL / L hydrofluoric acid and react for 5 seconds at room temperature Activation; two water washes again; passivation at room temperature for 2 minutes using the passivator of the example; then water washing and hot water washing, followed by drying.

[0053] The various process parameters of the above-mentioned passivated workpiece are: the surface of the w...

Embodiment 2

[0055] Prepare passivation solution:

[0056] Select chromium nitrate as the main film-forming salt, first dissolve chromium nitrate at a concentration of 8 g / L with an appropriate amount of water, then add 6 g / L oxalic acid, stir to dissolve, then add glycerin 3 g / L, stir to dissolve, and Heat the solution to 55°C and keep it warm for 2 hours, then add 2 g / L of nickel nitrate and stir to dissolve it, and then obtain the passivation solution after standing still.

[0057] Passivation process:

[0058] Degrease the passivated workpiece, use sodium silicate 40g / L, OP-10 emulsifier 3ml / L to wash at 60°C; use hydrofluoric acid 10ml / L, react at room temperature for 20 seconds Activation; two water washes again; using the passivator of this example, passivation at room temperature for 1 minute; then washing with water and then hot water and then drying.

[0059] The various process parameters of the workpiece after the above-mentioned passivation are:

[0060] The surface of the ...

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Abstract

The invention relates to an aluminium alloy trivalent chromium passivation solution as well as a preparation method and a passivation technology thereof. The aluminium alloy trivalent chromium passivation solution mainly contains chromic nitrate, complexing agents and a film forming accelerant, wherein the complexing agents contain a group of organic acid complexing agent and a group of polyhydroxy-alcohol complexing agent. The preparation method thereof comprises the steps of weighing raw materials in proportion, adding right amount of water for dissolution, adding the organic acid complexing agent and the polyhydroxy-alcohol complexing agent, preserving warm for two hours after heating the mixture to be at the temperature of 50-70 DEG C, finally adding the film forming accelerant, stirring and keeping still. The passivation technology comprises oil removing, hot water washing, activation, double washing, passivation, washing, hot water washing and drying. When the aluminium alloy trivalent chromium passivation solution disclosed by the invention is applied to the surface anticorrosive treatment of casting aluminum alloy parts, the corrosion resistance of the aluminium alloy is remarkably improved, the corrosion resistance time is over 480 hours, the price is reduced, and the production cost is significantly reduced.

Description

technical field [0001] The invention belongs to the technical field of metal surface treatment, and relates to an aluminum alloy trivalent chromium passivation solution, a preparation method thereof, and a passivation process using the passivation solution. Background technique [0002] The cast aluminum alloy used in automobiles is easily corroded without surface treatment. White corrosion spots will appear 2 to 4 hours after exposure to water, so anti-corrosion treatment is required. Previously, hexavalent chromium passivation can better meet the corrosion resistance requirements of aluminum alloys. However, the European Union and the United States have imposed strict restrictions on chemical substances used in automobiles. Whether it is the Rohs directive of the European Union or the laws of the United States, strict restrictions have been imposed on the content of harmful substances in complete vehicles and parts, and hexavalent The application of chromium in the surfac...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C23C22/56
Inventor 王宏
Owner 翊鹏(湖北)实业有限公司
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