Method of monopulse cyanide-free silver electroplating

A cyanide-free silver-plating, single-pulse technology, applied in the field of cyanide-free silver-plating solution and silver-plating, can solve the problems that the coating performance cannot meet the process requirements, the cyanide-free silver-plating is not widely used, and the stability is not good, and the appearance can be achieved. The effect of good color, strong throwing and covering ability, simple formula

Inactive Publication Date: 2014-03-26
NEW MATERIAL INST OF SHANDONG ACADEMY OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, due to the performance of the coating cannot meet the process requirements, poor stability, poor bonding and other problems, cyanide-free silver plating has not been widely used in the electroplating banking industry

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0011] Dissolve the following compounds in deionized water to prepare a cyanide-free silver plating solution:

[0012] Silver nitrate 30g / L Hydantoin 100g / L potassium pyrophosphate 40g / L potassium carbonate 80g / L pH value 10 temperature 20℃ brightener 10ml / L

[0013] The method of cyanide-free silver plating is as follows: (1) Pretreatment and pretreatment process of plated parts: degreasing of plated parts - water washing - pickling - water washing - pre-copper plating - water washing - pre-silver plating - water washing. (2) Keep the temperature of the heating bath at 20°C, apply a single-pulse electroplating power supply between the anode and the cathode, and control the average current density of the cathode to 0.4A / dm 2 , the duty cycle is 40%, the pulse period is 3ms, the cathode is mechanically stirred, and the electroplating is completed when the thickness of the coating reaches the requirement.

Embodiment 2

[0015] Dissolve the following compounds in deionized water to prepare a cyanide-free silver plating solution:

[0016] Silver nitrate 30g / L 5,5-Dimethylhydantoin 120g / L potassium pyrophosphate 40g / L potassium carbonate 80g / L pH value 10 temperature 20℃ brightener 5ml / L

[0017] The method of cyanide-free silver plating is as follows: (1) Pretreatment and pretreatment process of plated parts: degreasing of plated parts - water washing - pickling - water washing - pre-copper plating - water washing - pre-silver plating - water washing. (2) Keep the temperature of the heating bath at 20°C, apply a single-pulse electroplating power supply between the anode and the cathode, and control the average current density of the cathode to 0.8A / dm 2 , the duty cycle is 40%, the pulse period is 3ms, the cathode is mechanically stirred, and the electroplating is completed when the thickness of the coating reaches the requirement.

Embodiment 3

[0019] Dissolve the following compounds in deionized water to prepare a cyanide-free silver plating solution:

[0020] Silver nitrate 30g / L 1,3-dichloro-5,5-dimethylhydantoin 140g / L potassium pyrophosphate 40g / L potassium carbonate 80g / L pH value 6 temperature 20℃ brightener 5ml / L

[0021] The method of cyanide-free silver plating is as follows: (1) Pretreatment and pretreatment process of plated parts: degreasing of plated parts - water washing - pickling - water washing - pre-copper plating - water washing - pre-silver plating - water washing. (2) Keep the temperature of the heating bath at 20°C, apply a single-pulse electroplating power supply between the anode and the cathode, and control the average current density of the cathode to 0.4A / dm 2 , the duty cycle is 40%, the pulse period is 3ms, the cathode is mechanically stirred, and the electroplating is completed when the thickness of the coating reaches the requireme...

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PUM

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Abstract

The invention discloses components and a technology of a monopulse cyanide-free silver electroplating solution. The components and the technology are characterized in that: cyanide-free silver electroplating solution mainly comprises silver nitrate, hydantoin and derivatives thereof, potassium pyrophosphate, potassium sulfate, hydrochloric acid, deionized water, and the like. Operation conditions are that the pH value of the electroplating solution is 6-10 and that the temperature of the electroplating solution is 20-40 DEG C. A finely crystallized silver plating can be obtained through electroplating on pure copper or a copper alloy by utilizing of monopulse electroplating and by controlling the pulse width, the pulse duty cycle, the average pulse current density and the pulse working time. The electroplating solution is simple in formula, easy to control, strong in throwing power and in covering power and high in batch production stability. The plating is finely crystallized, and is good in appearance color. The plating is free from peeling, falling off and stripping. The technology can replace cyanide silver electroplating technologies, is environmental-friendly and pollution-free, and reduces damage of silver electroplating to operators.

Description

technical field [0001] The invention belongs to the technical field of electroplating chemistry, and in particular relates to a cyanide-free electroplating silver solution and a silver plating method. Background technique [0002] Metal silver plating has good electrical conductivity, weldability and low contact resistance. It is widely used in appearance decoration, electronic devices, transformers, and valuable instruments and meters. The current market is mainly based on cyanide silver plating process, which pollutes the environment and harms the environment. damage to the health of the operator. The cyanide-free silver plating solution uses cyanide-free ions as silver ion complexing agents to deposit silver plating layers through electrochemical reactions. However, due to the performance of the coating cannot meet the process requirements, poor stability, poor bonding and other problems, cyanide-free silver plating has not been widely used in the electroplating banking ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C25D3/46C25D5/18
Inventor 张晶王修春伊希斌马婕刘硕潘喜庆
Owner NEW MATERIAL INST OF SHANDONG ACADEMY OF SCI
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