Introduction
The electroplating of zinc is very common in the manufacturing process. It involves submerging a component or object into a bath of zinc and applying electrical current in order to deposit a thin layer of zinc onto the surface of the object. Zinc electroplating provides a number of benefits - it creates a chemical barrier that can prevent a component or object from rusting, improves electrical conductivity, and increases the aesthetic value of the finished product.
In order to achieve the desired results, the bath must contain the correct amounts of chemicals. The chemical formulations used for zinc electroplating may vary from one manufacturer to the next; so its important to follow the directions of your own supplier very carefully.
This article will outline the components and chemical makeup of a typical alkaline cyanide zinc electroplating bath.
The Components of an Alkaline Cyanide Zinc Electroplating Bath
An alkaline cyanide zinc electroplating bath contains the following components:
1. Zinc: Zinc is the main element that is plated onto the surface of the object, so it is crucial that the right amount is used in the bath. Too little zinc can result in inadequate coverage, while too much can create excessive zinc deposit buildup on the object.
2. Cyanide: Cyanide acts as a brightener in zinc electroplating baths and helps to produce a smoother finish. It also helps the zinc to stick better to the object being plated.
3. Alkaline Agent: Alkaline agents serve as buffers in the bath, controlling the pH level of the solution and helping to ensure that the zinc will plate correctly. Common alkaline agents used are potassium hydroxide, sodium hydroxide and ammonium hydroxide.
4. Surfactant: Surfactants are used in zinc plating baths to reduce surface tension and help ensure a uniform coating.
5. Activator: Activators are used to improve the adhesion of the zinc to the object being plated. Common activators used in alkaline cyanide baths are sulfuric acid and hydrochloric acid.
6. Brightener: Brighteners are used to enhance the luster and brightness of the zinc deposit on the object.
7. Wetting Agent: Wetting agents are used to help the solution flow more freely, particularly in tight corners and recesses that are difficult to reach.
Conclusion
The chemical composition of an alkaline cyanide zinc electroplating bath is important to ensure that the zinc plating process is done correctly and produces a quality finish. It is essential that the proper concentrations of each of the components are used in order to achieve the desired results. Furthermore, the bath should be monitored regularly to make sure that it remains in good condition.
