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Since the time of the ancient Egyptians, people have been trying to turn ordinary metals into valuable ones. Known as alchemy, this mystical process was eventually ruled out by science as being impossible. Today the closest we have to this could be considered electroplating. Just what is it? And how does this fascinating process work?

Although this metal finishing method dates back at least 200 years, it has been continually improved with new advances in the technology. These innovations have led to electroplating becoming used in almost all industries. However, despite its ubiquity and cutting-edge refinement, it’s often misunderstood and poorly implemented.

Let’s look at just what electroplating is and how we at MP Eastern apply rigorous standards to achieve industry leading results.

What is electroplating?

The oldest confirmed use of electroplating comes from 1805 and was developed by Italian chemist, Luigi Valentino Brugnatelli. There are archaeologists, however, who tentatively suggest that some relics, such as the Baghdad battery, which is nearly 2,000 years old, may have been used by ancient peoples to perform rudimentary electroplating. Regardless of when the method was developed, we can be certain that electroplating truly came into its own in the mid-1800s, with the first patents were granted to the Elkington brothers in Birmingham in 1840 and the the first modern electroplating plant was founded in Hamburg during 1876.

Since it's invention, the concept behind electroplating has remained the same:

Electroplating is used to change the surface properties of a material by covering it in a metal coating.

But what do we mean by ‘change the properties of a material?’ While there are numerous ways in which electroplating can be used to do this, the most common properties which electroplating gives to a material being covered, include:

  • Durability to wear and tear
  • Reduction in roughness and resulting abrasion of a material through increased lubricity
  • Protection from corrosion
  • A more appealing appearance, giving it a premium, shinier, or durable look

How does electroplating work?

Electroplating enables one material to be coated with another and take on its appearance. Coating a material to give it a new property or appearance is achieved through the use of an electric current. This is why, for the most part, the process only came into widespread use after the industrial revolution when electricity was widely available.

Two materials are used:

  • Substrate: This is whatever material is to be coated in metal.
  • Plating Metal: The metal to be applied to the substrate. Also known as the coating.

For example, a nickel finish to a product is often applied because it makes the substrate look brand new, beautiful, and gives it that sheen which says ‘quality’ to potential customers. It can be used to make most metals beautiful, including stainless steel, copper, brass, bronze, and aluminium. All it needs to do this is a suitable pre-treatment coat to ensure the nickel sticks to the substrate correctly.

With all that being said then, how does electroplating work? How is a metallic coating applied through electroplating?

A simple explanation of electroplating is that it uses electricity to ensure the metal coating ‘sticks’ to the substrate. Now, do you have your scientist hat on? Good, we never leave home without ours. Let’s get a little more technical:

This process of depositing metal onto another material is called electrodeposition. To do this, we need two components. One is called the anode and the other is called the cathode. These essentially work like a large battery. Unlike a normal battery, however, the electric charges are reversed. The anode is positively charged and the cathode is negatively charged. Both are immersed in a solution called an electrolyte. This solution is basically comprised of dissolved metal salts which facilitate the flow of electricity and are the reason the charges are reversed. An electrical current (DC) is then applied to the anode, and so the electricity flows from the anode, through the electrolyte solution, and to the cathode.

But what does this have to do with metal plating?

Well, the metal plating is connected to the anode. The substrate is connected to the cathode. When the electricity flows from the anode to the cathode, it dissolves some of the metal plating atoms, which then move through the electrolyte solution and are then drawn by the electrical current to the substrate material at the cathode.

Just like that, the substrate has been coated in a thin metal layer. You can take off your science hat, now. Unless it’s comfortable.

What makes quality electroplating?

Despite being an essential manufacturing process, poor quality electroplating is widespread. This happens when the electroplating process has not been carried out with diligence and the correct techniques. This results in product defects including:

  • Flaking of coating
  • Poor adhesion
  • Hydrogen cracking
  • Blistering
  • Oxidation
  • Discolouring through uneven appearance

At MP Eastern, we have extensive quality control procedures to ensure this does not happen. We guarantee a premium electroplating process through:

  • Precision application of any voltage used
  • Innovative chemical composition and temperature of our electrolyte solutions
  • Perfect distancing between cathode and anode
  • Years of know-how in selecting the correct duration for any specific electroplating task

Which metals are best for electroplating?

The beauty of electroplating is that numerous metal coatings can be used. Depending on the metal, each coating will have a unique look and a specific set of properties regarding durability, anti-corrosion, and lubricity. Alloys can also be created for bespoke purposes and used for metal plating.

Common metals used for electroplating include:

  • Copper: Perfect for coating premium threads on couplings and ancillaries.
  • Nickel: Great for both decorative and engineering purposes.
  • Zinc: Often used to create a protective coating to improve corrosion resistance or lubricity for the increased torque of fasteners and threads.

Where is electroplating used?

Electroplating is used in most manufacturing industries. It’s also used in a great many bespoke one-off or custom builds, including non-commercial projects.

Industries where electroplating is commonly used, include:

●    Fossil fuel extraction
●    Aerospace
●    Defence
●    Automotive and Motorsports
●    DIY

Electroplating Vs Electroless Plating

A competing option to electroplating is electroless plating. Electroless plating uses a process where the substrate is cleaned extensively. A catalyst is then used to create a series of chemical reactions on the surface of the substrate as thin layers of metal are applied. These chemical reactions produce an even coating which hardens over time.

Debate rages over which is best, but in our experience, it all depends on the materials you are using and how you need those materials to perform.

Electroplating regulations

Any business or individual who uses electroplating in their products must meet rigorous legal guidelines in order to electroplate safely. As a leading company within the surface coating industry, at MP Eastern we take these commitments seriously. We ensure at all times that we meet the many codes and practices required of us by law. As a member of the Surface Engineering Association, we are regularly provided with the best advice from both a technical and business standpoint, ensuring our commitment to all current and upcoming UK and EU legislation.

What to do next

For more information, advice, or a quote for your electroplating project, please contact us.