In the zinc alloy electroplating barrel plating process, the alkali cyanide cyanide electroplating is the most important task in the entire process. The level of a master's on-site control mainly determines the level of alkali copper that he controls. The author briefly discusses several points of view on his experience in zinc alloy plating for several years. :
First talk about bath composition;
The main salt; Cuprous cyanide: I believe that cyanide should be controlled at 50-100g / l is more appropriate, high cuprous content, the copper speed, high production efficiency, but more than 100 when the cuprous cyanide The problem has obviously increased, and the chance of blistering has increased a lot. When cuprous cyanide is too low, plating is slow and inefficient.
However, iron-based primers are generally not recommended in excess of 30 g/l, because the main salt is too high to affect the underlying aggregating force.
Complexing agent: sodium cyanide; suggest that sodium cyanide and copper cyanide keep a certain proportion, because complexing 1 g of copper cyanide requires 1.1 g of sodium cyanide, and our production always maintains a coefficient: total amount of sodium cyanide = 1.38 * Total amount of cuprous cyanide, when free cyanide is in the range of 1.38-1.1 = 0.28* cuprous cyanide, production control is generally normal, and free cyanide is controlled at "0.2-0.3*cyanide cyanide" during production. "The amount is more normal than normal and can ensure the dissolution of copper. If the free cyanide is too high, the brightness of the copper is poor, the current efficiency is low, and the smell of the workshop is heavy. The free cyanide is too low, the poor walk in the low zone, it is easy to foam, and the anode is passivated.
Potassium sodium tartrate: mainly activated anode, impurity removal performance, addition amount 25-30.
Jiaxing Dongxin Surface Treatment Material Co., Ltd. Nocer Liquid has both active anodes, de-miscibility and auxiliary brightening effect, and the addition amount is 30ml/l.
PH; zinc alloy electroplating barreling process PH is critical, the appropriate range of 10.5-12, PH is generally increased during electroplating process, when the electroplating solution is in a normal state, when the PH in the electroplating process down, indicating electroplating The anode is in an abnormal state - the anode is passivated. The anodic reaction; one is the dissolution of copper, and the other is the evolution of anodic oxygen, 2OH-2E=O2+2H+, so the anodic oxygen evolution releases the hydrogen ions and the pH decreases. When the pH is found to be lower in production, measures should be taken immediately to change the status, otherwise 2NaCN+2H2O+2NaOH+O2—2NaCO3+NH3, ie carbonate, will increase. Carbonate in the cyanide electroplating bath, a small amount is beneficial, it plays the role of light and conductive, but more than 70, the side effects will appear, the coating is loose, electroplating sometimes 2-3 hours after electroplating copper test acid or not . It consumes a lot of manpower and talent. At this time, there is a layer of dense gray film on the anode surface to affect the anode dissolution. If the current situation is not taken immediately, the area of ​​the anode is reduced, and the anode passivation will be more serious.
When the PH is over 12.5, the zinc plating will inevitably lead to zinc, and it is easy to make the plating yellow. If the temperature is high at this time, electroplating is easy to foam, and the pH can be lowered by tartaric acid neutralization.
Brightener; Jiaxing Dongxin Surface Treatment Material Company DX-3, DX-4 is a pure organic brightener, DX-3 is a high zone brightener in production and copper cyanide has a similar role, it makes the coating color reddish . DX-4 is a low-zone brightener that has a similar effect to sodium cyanide in production. Too much color is white. DX-3: DX-4 normally consumes 1:4. Under normal conditions, the mirror can be achieved within 50-70 minutes of electroplating, which lays a good foundation for subsequent electroplating.
Temperature; generally 40-55°C. When the temperature is too high, the workshop environment is poor, energy is wasted, and decomposition of sodium cyanide is accelerated. If the temperature is too low, the speed is slow, the efficiency is low, and the brightness is poor
Then there is the electroplating anode; the electroplating of zinc alloy plating requires fast plating and dense plating. The anodic dissolution is required to be normal. Therefore, the area of ​​the anode is required to be sufficient. It is not appropriate to directly hang the copper plate on the anode. Instead, the copper plate should be cut into small pieces and put into titanium blue to increase the area of ​​the anode. Usually, only sodium cyanide and cyanide need to be maintained. Copper is supplemented by anodic dissolution.
The plating solution of copper in the electroplating layer of the anodic dissolution supplementary plating solution is dense. In general, the copper plating layer of the cyanidized cuprous chloride is not dense, and the plating cost is high. It has been proved that the anodic dissolution of the bath carbonate will not exceed the standard. The normal dissolution of the copper anode is slightly dark red, too bright, and the free cyanide is too high. The syrup is blue, the anode is green, and the free cyan is too low. Gray, carbonate is too high. Blackening; lead impurities, coating is easy to have spots.
Equipment: The drum should generally be designed to have a small diameter and a long shape so that the plating is uniform and the plating speed is high.
Conductive copper bars generally require thicker, because the zinc alloy plating current is relatively large.
First talk about bath composition;
The main salt; Cuprous cyanide: I believe that cyanide should be controlled at 50-100g / l is more appropriate, high cuprous content, the copper speed, high production efficiency, but more than 100 when the cuprous cyanide The problem has obviously increased, and the chance of blistering has increased a lot. When cuprous cyanide is too low, plating is slow and inefficient.
However, iron-based primers are generally not recommended in excess of 30 g/l, because the main salt is too high to affect the underlying aggregating force.
Complexing agent: sodium cyanide; suggest that sodium cyanide and copper cyanide keep a certain proportion, because complexing 1 g of copper cyanide requires 1.1 g of sodium cyanide, and our production always maintains a coefficient: total amount of sodium cyanide = 1.38 * Total amount of cuprous cyanide, when free cyanide is in the range of 1.38-1.1 = 0.28* cuprous cyanide, production control is generally normal, and free cyanide is controlled at "0.2-0.3*cyanide cyanide" during production. "The amount is more normal than normal and can ensure the dissolution of copper. If the free cyanide is too high, the brightness of the copper is poor, the current efficiency is low, and the smell of the workshop is heavy. The free cyanide is too low, the poor walk in the low zone, it is easy to foam, and the anode is passivated.
Potassium sodium tartrate: mainly activated anode, impurity removal performance, addition amount 25-30.
Jiaxing Dongxin Surface Treatment Material Co., Ltd. Nocer Liquid has both active anodes, de-miscibility and auxiliary brightening effect, and the addition amount is 30ml/l.
PH; zinc alloy electroplating barreling process PH is critical, the appropriate range of 10.5-12, PH is generally increased during electroplating process, when the electroplating solution is in a normal state, when the PH in the electroplating process down, indicating electroplating The anode is in an abnormal state - the anode is passivated. The anodic reaction; one is the dissolution of copper, and the other is the evolution of anodic oxygen, 2OH-2E=O2+2H+, so the anodic oxygen evolution releases the hydrogen ions and the pH decreases. When the pH is found to be lower in production, measures should be taken immediately to change the status, otherwise 2NaCN+2H2O+2NaOH+O2—2NaCO3+NH3, ie carbonate, will increase. Carbonate in the cyanide electroplating bath, a small amount is beneficial, it plays the role of light and conductive, but more than 70, the side effects will appear, the coating is loose, electroplating sometimes 2-3 hours after electroplating copper test acid or not . It consumes a lot of manpower and talent. At this time, there is a layer of dense gray film on the anode surface to affect the anode dissolution. If the current situation is not taken immediately, the area of ​​the anode is reduced, and the anode passivation will be more serious.
When the PH is over 12.5, the zinc plating will inevitably lead to zinc, and it is easy to make the plating yellow. If the temperature is high at this time, electroplating is easy to foam, and the pH can be lowered by tartaric acid neutralization.
Brightener; Jiaxing Dongxin Surface Treatment Material Company DX-3, DX-4 is a pure organic brightener, DX-3 is a high zone brightener in production and copper cyanide has a similar role, it makes the coating color reddish . DX-4 is a low-zone brightener that has a similar effect to sodium cyanide in production. Too much color is white. DX-3: DX-4 normally consumes 1:4. Under normal conditions, the mirror can be achieved within 50-70 minutes of electroplating, which lays a good foundation for subsequent electroplating.
Temperature; generally 40-55°C. When the temperature is too high, the workshop environment is poor, energy is wasted, and decomposition of sodium cyanide is accelerated. If the temperature is too low, the speed is slow, the efficiency is low, and the brightness is poor
Then there is the electroplating anode; the electroplating of zinc alloy plating requires fast plating and dense plating. The anodic dissolution is required to be normal. Therefore, the area of ​​the anode is required to be sufficient. It is not appropriate to directly hang the copper plate on the anode. Instead, the copper plate should be cut into small pieces and put into titanium blue to increase the area of ​​the anode. Usually, only sodium cyanide and cyanide need to be maintained. Copper is supplemented by anodic dissolution.
The plating solution of copper in the electroplating layer of the anodic dissolution supplementary plating solution is dense. In general, the copper plating layer of the cyanidized cuprous chloride is not dense, and the plating cost is high. It has been proved that the anodic dissolution of the bath carbonate will not exceed the standard. The normal dissolution of the copper anode is slightly dark red, too bright, and the free cyanide is too high. The syrup is blue, the anode is green, and the free cyan is too low. Gray, carbonate is too high. Blackening; lead impurities, coating is easy to have spots.
Equipment: The drum should generally be designed to have a small diameter and a long shape so that the plating is uniform and the plating speed is high.
Conductive copper bars generally require thicker, because the zinc alloy plating current is relatively large.