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A kind of alkaline chromium-free passivation solution and the method for normal temperature passivation electroless ni-p layer thereof

A chrome-free passivation and passivation solution technology, which is applied in the coating process of metal materials, can solve the problems of human body and environment poisoning, heating, etc., and achieve the effects of low cost, excellent performance and excellent discoloration resistance

Active Publication Date: 2018-04-13
SOUTH CHINA UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] In view of the toxicity of the existing electroless Ni-P layer hexavalent chromium passivation process to the human body and the environment, and the problem that heating is still required during passivation treatment, the purpose of the present invention is to provide an alkaline chromium-free passivation solution

Method used

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  • A kind of alkaline chromium-free passivation solution and the method for normal temperature passivation electroless ni-p layer thereof
  • A kind of alkaline chromium-free passivation solution and the method for normal temperature passivation electroless ni-p layer thereof
  • A kind of alkaline chromium-free passivation solution and the method for normal temperature passivation electroless ni-p layer thereof

Examples

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Embodiment 1

[0036] A method for passivating an electroless Ni-P layer with an alkaline chromium-free passivation solution at normal temperature, comprising the steps:

[0037] (1) Sample preparation: use low-carbon steel (A3) as the plating substrate for electroless Ni-P plating, cut the steel plate into 20×50×3mm samples, and punch holes at one end of the sample for hanging;

[0038] (2) Pre-plating treatment: The cut steel sheet is processed according to the following process, grinding → degreasing → water washing → activation → water washing; among them, sandpaper of different grain sizes is used for grinding from low to high (500#→1000#→1500# ) in a step-by-step grinding manner; degreasing is alkaline degreasing at room temperature for 10 minutes, and the composition of the degreasing liquid is: NaOH 30g / L, NaOH 2 CO 3 10g / L, sodium dodecylbenzene sulfonate 5.0g / L; activation refers to the use of 5.0wt% HCl solution, activation at room temperature for 20s, and electroless Ni-P platin...

Embodiment 2

[0043] A kind of method of alkaline chromium-free passivation solution normal temperature passivation chemical plating Ni-P layer, comprises the steps:

[0044] Steps (1)-(3) are the same as in Example 1;

[0045] (4) Preparation of alkaline chromium-free passivation solution at room temperature: prepare 1000ml of passivation solution, pour 700ml of distilled water into a clean beaker, and add in sequence: Ba(OH) 2 30.0g, NaOH 2.0g, triethanolamine 6.0g, NaVO 3 10.0g, NaClO (10.0wt.%) 10.0g, sodium persulfate 10.0g, sodium citrate 5.0g, sodium acetate 3.0g, during the addition process, the former should be completely dissolved and stirred evenly before adding the latter Reagent, after the addition is completed, add distilled water to a total volume of 950ml, adjust the pH of the solution to 13.0, add distilled water to 1000ml, and obtain an alkaline chromium-free passivation solution;

[0046] (5) Passivation treatment: immerse the chemically plated Ni-P layer steel in an al...

Embodiment 3

[0048] A method for passivating an electroless Ni-P layer with an alkaline chromium-free passivation solution at normal temperature, comprising the steps:

[0049] Steps (1)-(3) are the same as in Example 1;

[0050] (4) Preparation of alkaline chromium-free passivation solution at room temperature: prepare 1000ml of passivation solution, pour 700ml of distilled water into a clean beaker, and add in sequence: Ba(OH) 2 12.0g, NaOH 8.0g, triethanolamine 4.0g, NaVO 3 18.0g, NaClO (10.0wt.%) 12.0g, sodium persulfate 6.0g, sodium oxalate 3.0g, sodium acetate 5.0g, during the addition process, the former reagent should be completely dissolved and stirred evenly before adding the latter reagent After the addition is completed, add distilled water to a total volume of 950ml, adjust the pH of the solution to 11.0, add distilled water to 1000ml, and obtain an alkaline chromium-free passivation solution;

[0051] (5) Passivation treatment: immerse the chemically plated Ni-P layer steel...

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Abstract

The invention belongs to the technical field of metal material surface treatment, and discloses alkaline chromate-free passivation liquid and a method for normal temperature passivation of a chemical Ni-P plated layer through the alkaline chromate-free passivation liquid. The alkaline chromate-free passivation liquid is prepared by adjusting the pH of vanadate passivation liquid through an acid-base adjusting agent to be alkaline; and the vanadate passivation liquid comprises barium hydroxide, sodium hydroxide, triethanolamine, vanadate, an oxidizing agent and a stabilizer, wherein the concentration of the barium hydroxide ranges from 1.0 g / L to 30.0 g / L, the concentration of the sodium hydroxide ranges from 1.0 g / L to 15.0 g / L, the concentration of the triethanolamine ranges from 1.0 g / L to 10.0 g / L, the concentration of the vanadate ranges from 1.0 g / L to 30.0 g / L, the concentration of the oxidizing agent ranges from 2.0 g / L to 35.0 g / L, and the concentration of the stabilizer ranges from 2.0 g / L to 15.0 g / L. The passivation liquid is simple in composition, low in cost, safe, environment-friendly and small in equipment corrosion; and a passivation coating obtained after normal temperature treatment is colorless and transparent, and good color-changing resistance and good decay resistance are achieved.

Description

technical field [0001] The invention belongs to the technical field of metal material surface treatment, in particular to an alkaline chromium-free passivation solution and a passivation method for using the passivation solution to passivate an electroless Ni-P layer at normal temperature. Background technique [0002] Electroless Ni-P alloy plating has good throwing ability, compactness, smooth surface, excellent corrosion resistance and wear resistance, no vacuum conditions are required during plating, less pollution, and lower process temperature; at the same time, it does not require expensive, Special equipment conditions, and can be deposited on metal and non-metal (glass, ceramics and plastics, etc.) substrates. In addition, by adjusting the P content of the coating, the crystalline properties of the coating can also be changed. Many advantages make Ni-P coatings widely used in aerospace, petroleum, chemical, national defense, energy and other industrial sectors. [...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C23C22/60C23C18/36
CPCC23C18/36C23C22/60
Inventor 穆松林杨思嘉杜兴灿李文芳杜军
Owner SOUTH CHINA UNIV OF TECH