The main difference between electroplating and galvanisation is that electroplating is a process in which a thin layer of one metal is deposited onto the surface of another metal using electricity, whereas galvanisation is a process that involves coating steel or iron with a layer of zinc to protect it from corrosion.
Electroplating and galvanisation are two distinct metal coating processes used for various purposes in industry and manufacturing. Both processes play critical roles in enhancing the longevity and functionality of metal objects.
Key Areas Covered
1. What is Electroplating
– Definition, Features, Applications
2. What is Galvanisation
– Definition, Features, Applications
3. Similarities Between Electroplating and Galvanisation
– Outline of Common Features
4. Difference Between Electroplating and Galvanisation
– Comparison of Key Differences
5. FAQ: Electroplating and Galvanisation
– Frequently Asked Questions
Key Terms
Electroplating, Galvanisation, Electro-galvanising, Hot-dip Galvanising, 
What is Electroplating
Electroplating is based on the principles of electrochemistry, specifically the reduction-oxidation (redox) reactions. The process involves immersing the object to be plated, known as the substrate or workpiece, into a solution containing a metal salt of the plating material. The workpiece is then connected to the cathode (negative terminal), and a piece of the desired metal, which acts as the anode (positive terminal), is also immersed in the solution. When an electrical current is applied, metal ions from the solution are reduced and form a thin, even layer on the surface of the workpiece.
Figure 1: Electroplating
Electroplating is a versatile process with multiple applications. Most use it for decorative purposes, adding lustrous finishes to objects like jewelry and cutlery. Electroplating also offers corrosion protection, with chrome and other metals used to safeguard surfaces against rust. In electronics, it enhances electrical conductivity by applying metals like silver. It improves wear resistance for industrial components through the deposition of hard materials like nickel. Electroplating can reduce friction and provide self-lubrication in moving parts. In the electronics industry, it enhances solderability. The process creates reflective surfaces for mirrors, optical instruments, and antimicrobial surfaces in healthcare settings to reduce pathogen transmission.
What is Galvanisation
Galvanisation is a process that coats iron or steel with a layer of zinc in order to protect the metal from corrosion. This protective zinc coating is applied by either hot-dip galvanising or electro-galvanising.
In hot-dip galvanising, the steel or iron object is immersed in a bath of molten zinc at a high temperature. The zinc bonds to the metal’s surface, forming a strong and durable protective layer that prevents rust and corrosion. This process is commonly used for large and heavy items like steel beams, pipes, and outdoor structures.
Electro-galvanising, on the other hand, involves immersing the metal object in an electrolyte solution containing zinc ions. An electrical current is applied, causing the zinc ions to bond with the metal surface, creating a thin but effective protective layer. Electro-galvanising is often useful for smaller, more intricate items.
Figure 2: Galvanised Surface
Galvanisation is useful in various industries, including construction, automotive, and manufacturing, where the prevention of rust and corrosion is crucial for the longevity and integrity of metal components and structures. It’s an effective and cost-efficient method for extending the life of iron and steel products exposed to harsh environmental conditions.
Similarities Between Electroplating and Galvanisation
- Electroplating and galvanising involve the deposition of a metal coating onto another material.
- Both processes employ a sacrificial metal to protect the material being coated.
Difference Between Electroplating and Galvanisation
Definition
Electroplating is a process in which a thin layer of one metal is deposited onto the surface of another metal using electricity, whereas galvanisation is a process that involves coating steel or iron with a layer of zinc to protect it from corrosion.
Product
While electroplating typically produces thin, precise coatings, often measured in micrometers, galvanising produces relatively thick coatings, measured in tens to hundreds of micrometers.
Coating Material
Electroplating uses various metals, depending on the application (e.g., gold, silver, nickel, chrome, copper, etc.), whereas galvanisation only uses zinc.
Process
In electroplating, the material to be coated (the object) is submerged in an electrolyte solution containing metal salts, while galvanising typically involves immersing iron or steel objects into a bath of molten zinc.
FAQ: Electroplating and Galvanisation
Is galvanising a type of electroplating?
No, galvanising is not a type of electroplating. Galvanising is a distinct process that helps to protect iron or steel from corrosion by coating it with a layer of zinc, while electroplating is a separate process that helps to apply various metals, such as gold or silver, for decorative, conductive, or protective purposes on a wide range of materials. Meanwhile, electrolytic galvanising is the process of coating steel in zinc by using electroplating.
What are the disadvantages of electroplating?
Disadvantages of electroplating include environmental concerns due to the use of toxic chemicals, the need for precise control to achieve even coatings, and the potential for high energy consumption during the process.
What is the difference between hot dip galvanising and zinc electroplating?
Hot-dip galvanising immerses steel in molten zinc, creating a thicker, more robust protective layer against corrosion, often used for large items. Zinc electroplating applies a thinner zinc coating through an electrochemical process, typically for smaller, intricate objects, and can serve decorative and functional purposes.
Conclusion
Electroplating is a process in which a thin layer of one metal is deposited onto the surface of another metal using electricity. In contrast, galvanisation is a process that involves coating steel or iron with a layer of zinc to protect it from corrosion. This is the main difference between electroplating and galvanisation.
Reference:
1. “galvanisation.” Wikipedia. Wikipedia Foundation.
2. “Electroplating.” Science Direction.
Image Courtesy:
1. “Feuerverzinktes Geländer” By TMg – Own work (CC BY-SA 3.0 de) via Commons Wikimedia
2. “Copper electroplating principle (multilingual)” By Torsten Henning (Multilingual Perhelion) – Own work (Public Domain) via Commons Wikimedia
Leave a Reply