Difference Between Zinc and Nickel Plating

The key difference between zinc and nickel plating is that zinc plating involves applying a thin coating of zinc on a conductive substance whereas nickel plating involves the application of a thin layer of nickel on a metal surface. Moreover, in zinc coating, the lifetime of the substrate increases but, in nickel plating the lifespan of coating is limited.

Zinc and nickel plating are very important processes we can use as protective methods for electrical conducting materials. However, zinc-nickel plating is a different method that we should not confuse with these two methods.

CONTENTS

1. Overview and Key Difference
2. What is Zinc Plating
3. What is Nickel Plating
4. Side by Side Comparison – Zinc vs Nickel Plating in Tabular Form
5. Summary

What is Zinc Plating?

Zinc plating is galvanization in which we apply a thin layer of zinc on the surface of a conductive material. It is a protection method for iron and steel in order to protect them from rusting.

Furthermore, this technique mainly involves the electrodeposition of zinc on the substrate. Also, the most common method of this plating is hot-dip galvanization in which we dip the substrate in a hot bath of molten zinc. However, we can use electroplating as well. The electroplating process includes the following steps:

1. Surface preparation
2. Preparing the plating solution
3. Introduction of electrical current
4. Post-treatment

Although these steps seem simple, zinc plating is a very complicated process which requires sophisticated equipment. Moreover, the zinc layer acts as a sacrificial coating on the surface of the substrate. That means; the zinc undergoes oxidation, but not the substrate.

Pros and Cons of Zinc Plating

Pros

• Production of zinc metal requires less energy
• Requires low levels of fuels during fabrication
• Zinc is recyclable
• The lifetime of the substrate increases
• Low toxicity levels

Cons

• Condensation of moisture on the coating may increase corrosion
• High cost of production
• Not suitable for too large or too small structures

What is Nickel Plating?

Nickel plating is a type of electroplating in which a thin layer of nickel is applied on the surface of a substrate. Here, we can apply the nickel layer as a decorative coating as well. Moreover, nickel plating provides corrosion resistance and wear resistance. Also, we can use this method to build up worn parts of objects.

Before plating begins, we need to make sure the substrate surface is free of dirt, corrosion, and defects. For the cleaning of the substrate surface, we can use different methods such as heat treating, masking, pickling, and etching. Thereafter, we can immerse the substrate in an electrolyte solution. Here, nickel acts as the anode while the substrate is the cathode. Nickel anode dissolves into the electrolytic solution followed by deposition on the substrate.

Pros and Cons of Nickel Plating

Pros

• Can achieve even coating on the surface
• Sophisticated equipment is not required
• Flexibility in plating volume and thickness
• Can blind holes with a stable thickness
• Can obtain a bright or semi-bright finish

Cons

• The lifespan of coating is limited
• Waste treatment cost is high
• Expensive

What is the Difference Between Zinc and Nickel Plating?

Zinc and nickel plating are types of metal plating methods we can use for decorative purposes and to protect the surfaces of other metals. The key difference between zinc and nickel plating is that the zinc plating involves applying a thin coating of zinc on a conductive substance whereas nickel plating involves the application of a thin layer of nickel on a metal surface. Also, another difference between zinc and nickel plating is that zinc plating can be done either as a hot dip galvanization or via electroplating method while nickel plating is mainly done using the electroplating method.

Furthermore, the difference between zinc and nickel plating in terms of their pros and cons is that compared to the nickel plating process, zinc plating requires less energy since the production of zinc requires a low amount of energy. Moreover, when considering the cost of production, nickel plating is comparatively inexpensive because it does not require sophisticated equipment; zinc plating requires a high cost for production. However, the product obtained from nickel plating is often expensive due to its bright finish and its ability to blind holes stably.

The below info-graphic summarizes the difference between zinc and nickel plating comparatively.

Summary – Zinc vs Nickel Plating

In conclusion, zinc plating and nickel plating are very important processes in the industry. The key difference between zinc and nickel plating is that the purpose of zinc plating is to apply a thin coating of zinc on a conductive substance whereas nickel plating involves the application of a thin layer of nickel on a metal surface.

Reference:

1. A. Yli-Pentti, in Comprehensive Materials Processing, 2014.

Image Courtesy:

1. “Galvanized surface” By The original uploader was Splarka at English Wikipedia. – Moreover, transferred from en.wikipedia to Commons (Public Domain) via Commons Wikimedia
2. “Electrolytic nickel” By Jurii –  (CC BY 3.0) via Commons Wikimedia