What is zinc electroplating and how zinc plating process works? These are a few common questions asked by the manufacturers. Today we will find answers to these frequently asked questions.
What is zinc electroplating?
Zinc electroplating is the process of depositing the layer of zinc on the surface of the metal substrate to protect it against the corrosion ( ). Zinc plating is used as the protective coating of metal parts such as nuts, bolts, machinery parts, automotive parts, and various other metal items.
How does zinc electroplating process work?
Zinc electroplating is a little complex process than other types of electroplating and requires a high level of expertise. Below is the step by step guide on how zinc plating works:
1. Cleaning the Metal Substrate
First of all metal substrate is cleaned using an alkaline detergent. It is necessary to clean the metal substrate because any contaminants present on the surface will prevent the zinc coating from properly adhering to the surface of the metal. To clean the metal substrate; it is soaked in the alkaline bath for five to ten minutes at about 150°F. This removes the soil and dirt from the surface of the metal substrate and cleans it thoroughly.
2. Pickling of the Substrate
It is also the part of preparing the metal substrate. In this process, a substrate is submerged into the acid solution to remove the oxide and scale which formed during the machining process. This process is also called activation of the substrate. The type of acid, dipping time and temperature of the bath will depend on the type of metal and thickness of the scale.
3. Preparing the Plating Solution
After preparing the metal substrate, it is required to immerse into the specialized electrolyte solution. This electrolyte solution contains the zinc metal ions and various other chemicals that facilitate the process. The plating bath is of two types- Acid zinc bath and Alkaline zinc bath. Preparing the proper plating solution help produce the desired chemical and physical properties of the metal plating.
4. Electroplating Zinc
After immersing the metal substrate into the plating bath, a DC current is passed through the solution. Metal substrate acts as cathode and zinc metal ions get deposited on the metal substrate with the help of electric current. Depending on the size and shape of the metal part ( ), zinc metal ions can be plated either using Rack plating or Barrel plating. Rack plating is used for larger metal parts, and Barrel plating is used for smaller metal parts
5. Post-treatment Procedure
It includes rinsing the treated metal substrate with water and drying it. This removes the remaining contaminants from the surface of the metal substrate.
So, this was the complete guide on zinc electroplating process.