No one has ever accused zinc of being pretty – particularly when used in combination with another metal such as iron. Unlike other metals such as gold, silver or even nickel, zinc is employed in zinc plating for its purely functional or engineering properties. This inorganic metal is often deposited on iron or steel using electrodeposition. An external electric current is employed. The process is called electroplating, however, in the case of zinc plating it is often called electro-galvanization.
Zinc plating is a method of application that can be employed with any metal as the substrate. However, the process is most commonly employed to plate two metals. These are steel and iron. Such a coating may or may not be tied together with chromate conversion coating. Zinc may also be employed with nickel or iron. Such alloys are commonly employed in various industries as a means of strengthening the ability to impart or enhance the desired qualities to the metal substrate surface.
Factors in Selecting a Zinc Plating Process
A company that plans to execute a zinc plating service needs to be certain its technicians understand exactly what processes are available to choose from – although this may be restricted by specializing in certain shops. It is important to consider the following factors before going ahead with the treatment.
- Is the plating specification for the component a zinc or a zinc alloy deposit?
- What is the substrate(s)?
- What is the corrosion protection required by the client?
- What are the thickness and the uniformity of the deposit required and requested?
- What are the characteristics of the deposit e.g. adhesion appearance, ductility?
- What will be the costs involved?
- Are there specific environmental concerns or restrictions?
These factors all need to be considered when selecting the type of zinc plating as well as the solution.
Types of Zinc Plating Solutions
There are several types of zinc plating solutions. They are specific to the type of plating performed. For strictly zinc plating, the most common ones are:
- Acid chloride
- Alkaline non-cyanide
- Cyanide
While others exist, these are the ones most widely employed in the zinc plating process to create corrosion resistant parts for various industries.
Zinc Plating and Industry
One common application of zinc plating is the automotive industry. This manufacturing concern utilizes components that have been zinc plated with regularity. Other industries, however, have employed zinc plating for their components. Zinc plated items include:
- Automotive bodies – undercoat for paint
- Bolts
- Engines
- Gas filters
- Nails
- Nuts
- Washers
These are a few of the parts that receive a zinc plating. Companies select this process over others for several reasons.
Why Zinc Plating?
Zinc plating is a popular and common form of electroplating. It is chosen because of its low cost as well as its ability to protect items from corrosion. All these factors, together with an increase in more environmentally friendly approach, contribute to the currently growing interest in zinc plating in the automotive and other industries.