Electroplating and chemical plating combined plating solution used for zinc die cast alloy

A technology of electroless plating and electroplating solution, which is applied in the field of surface treatment, can solve the problems of poor bonding between the nickel plating layer and the substrate, the application range is not very wide, and the cost of neutral nickel plating is high, so as to achieve low production cost and high corrosion resistance , the effect of improving economic benefits

Inactive Publication Date: 2016-03-16
张颖
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] Neutral nickel pre-plating is mainly used for the rack plating process of zinc alloy die castings, and the main component of the plating solution is NiSO 4 , sodium citrate, etc., do not contain cyanide, but the bonding force between the nickel plating layer and the substrate is far inferior to the performance of cyanide copper plating pre-plating, and the product qualification rate is low
Moreover, due to the poor activation ability of the neutral nickel plating solution on zinc alloy die castings, there are higher requirements for its pretreatment
The neutral nickel plating process generally cannot be used for barrel plating of zinc alloy die castings, therefore, the range of industrial applications is not very wide
In addition, the cost of neutral nickel plating solution is high, and wastewater treatment is difficult, which limits its large-scale application in industry.
[0007] Other zinc alloy die casting pre-plating processes include chemical copper plating, HEDP copper plating, copper-tin alloy electroplating, etc., all of which have not been practically applied in industry due to problems such as bonding force, cost, and wastewater treatment.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0019] A combined electroplating and electroless plating solution for die-casting zinc alloys, the combined solution includes two parts: an electroplating solution for cyanide-free pre-plating copper and an electroless nickel plating solution, wherein the composition of the cyanide-free copper pre-plating solution is coke Copper phosphate 100g / L; sodium pyrophosphate 50g / L, trisodium citrate 280g / L, potassium sodium tartrate 30g / L, HEDP30g / L, ethylenediamine 280g / L; ammonium bifluoride 2g / L; sodium fluoride 3g / L, lithium fluoride 6g / L; ammonia water to adjust the pH value to 9.5; electroless nickel plating bath composition: NiSO 4 ·6H 2 O30g / L, C 6 h 8 o 7 ·H 2 O4g / L, lactic acid 3g / L, propionic acid 1.5g / L, HF (40%) 16mL / L, NH 4 HF 2 16g / L, NaH 2 PO 2 ·H 2 O14g / L, NH 3 ·H 2 O22mL / L, thiourea 2mg / L, pH value 5.5, the two plating solutions are configured and stored separately. When in use, first use the electroplating solution for cyanide-free pre-plating copper for...

Embodiment 2

[0021] A combined electroplating and electroless plating solution for die-casting zinc alloys, the combined solution includes two parts: an electroplating solution for cyanide-free pre-plating copper and an electroless nickel plating solution, wherein the composition of the cyanide-free copper pre-plating solution is coke Copper phosphate 120g / L; sodium pyrophosphate 40g / L, trisodium citrate 300g / L, potassium sodium tartrate 26g / L, HEDP50g / L, ethylenediamine 260g / L; ammonium bifluoride 3g / L; sodium fluoride 2g / L, lithium fluoride 8g / L; ammonia water to adjust the pH value to 8.5; electroless nickel plating bath composition: NiSO 4 ·6H 2 O40g / L, C 6 h 8 o 7 ·H 2 O2g / L, lactic acid 5g / L, propionic acid 0.5g / L, HF (40%) 20mL / L, NH 4 HF 2 14g / L, NaH 2 PO 2 ·H 2 O16g / L, NH 3 ·H 2 O20mL / L, thiourea 4mg / L, pH value 4.5, the two plating solutions are configured and stored separately. When in use, first use the plating solution for cyanide-free pre-plating copper for cyanid...

Embodiment 3

[0023] A combined electroplating and electroless plating solution for die-casting zinc alloys, the combined solution includes two parts: an electroplating solution for cyanide-free pre-plating copper and an electroless nickel plating solution, wherein the composition of the cyanide-free copper pre-plating solution is coke Copper phosphate 110g / L; sodium pyrophosphate 45g / L, trisodium citrate 290g / L, potassium sodium tartrate 28g / L, HEDP40g / L, ethylenediamine 270g / L; ammonium bifluoride 2.5g / L; sodium fluoride 2.5g / L, lithium fluoride 7g / L; ammonia water to adjust the pH value to 9; electroless nickel plating bath composition: NiSO 4 ·6H 2 O35g / L, C 6 h 8 o 7 ·H 2 O3g / L, lactic acid 4g / L, propionic acid 1.0g / L, HF (40%) 18mL / L, NH 4 HF 2 15g / L, NaH 2 PO 2 ·H 2 O15g / L, NH 3 ·H 2 O21mL / L, thiourea 3mg / L, pH value 5.0; the two plating solutions are configured and stored separately. When in use, first use the electroplating solution for cyanide-free pre-plating copper fo...

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PUM

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Abstract

The invention discloses an electroplating and chemical plating combined plating solution used for zinc die cast alloy. The combined plating solution comprises a cyanide-free pre-electroplated copper electroplating solution and a chemical nickel-plating electroplating solution. The cyanide-free pre-electroplated copper electroplating solution comprises 100-120 g/L of cupric pyrophosphate, 40-50 g/L of sodium pyrophosphate, 280-300 g/L of trisodium citrate, 26-30 g/L of sodium potassium tartrate tetrahydrate, 30-50 g/L of HEDP, 260-280 g/L of ethidene diamine, 2-3 g/L of ammonium hydrogen difluoride, 2-3 g/L of sodium fluoride and 6-8 g/L of lithium fluoride, wherein the pH value of ammonium hydroxide is adjusted to be 8.5-9.5. The chemical nickel-plating electroplating solution comprises 30-40 g/L of NiSO4.6H2O, 2-4 g/L of C6H8O7.H2O, 3-5 g/L of lactic acid, 0.5-1.5 g/L of propionic acid, 16-20 mL/L of HF(40%), 14-16 g/L of NH4HF2, 14-16 g/L of NaH2PO2.H2O, 20-22 mL/L of NH3.H2O and 2-4 mg/L of thiourea, and the pH value is 4.5-5.5. The two electroplating solutions are matched and stored independently, during using, the cyanide-free pre-electroplated copper electroplating solution is used for carrying out cyanide-free electroplated copper bottoming firstly, and then the chemical nickel-plating electroplating solution is used for carrying out chemical nickel plating.

Description

technical field [0001] The invention relates to the field of surface treatment, in particular to a combined electroplating and electroless plating bath for die-casting zinc alloys. Background technique [0002] Due to its cheap price, low melting point, and especially good die-casting process performance, zinc alloy has been widely used in the manufacture of small hardware accessories, and can also be used to manufacture decorative and practical metal parts. Such as various zippers, belt buckles, luggage accessories, car nameplates and military badges, etc. [0003] The appearance of zinc alloy die castings is gray and white, and there are various defects on the surface, such as: slag inclusions, shrinkage cavities, etc. Therefore, without surface treatment, its usability and decoration are very poor. A common surface treatment method is electroplating. According to the different decorative and functional requirements, there are certain differences in the electroplating pr...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C25D3/38C23C18/36
CPCC25D3/38C23C18/36
Inventor 张颖
Owner 张颖
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