We have all heard of metal plating but why are objects coated in metal in this way? Plating is a process that occurs during manufacturing where a thin metal layer is added to a substrate. It is done to provide additional properties and qualities that the product would not otherwise have. There are two ways this can be done – using electricity to run a current through known as electroplating and electroless plating which relies on a chemical process.
The benefits of using this process in manufacturing include:
- To make a product more aesthetically pleasing
- To improve resistance to corrosion
- To improve paint adhesion
- Improve the ability to solder the object
- Make the object harder
- Lower friction rate
- To change the object’s conductivity
- To increase the amount of magnetism
Nickel Plating – Nickel is the ideal choice for electroless plating. Nickel has an attractive finish and so is often used to coat common household items such as door handles and shower fittings. It also offers strong protection against wear and tear. Electroless plating is done using phosphorus. The higher the phosphorus amount, the harder and more resistant to corrosion the nickel will be. Find out more about PTFE Coating at a site like Poeton
Copper Plating – This is a cost effective choice and also offers high conductivity. This is why it is commonly used in electronics. Thanks to its strong plating properties and relative cheapness, copper is a popular plating choice.
Zinc Plating – Zinc is another inexpensive plating substance that is often used as a galvanising coat on metal surfaces. It can be used in electroplating techniques, as a spray and dipped in a molten bath.
Chrome Plating – Chrome is primarily a decorative coating but it can be used for industrial components where corrosion or exposure is considered to be an issue and this is known as hard chrome plating. Chromium is often applied over nickel in the production of car trims and furniture, for example. Chromate can also be applied over zinc plating to change the colour of the metal.
Tin Plating – Tin plating is commonly seen in the packaging for food and drink. Coated over steel, it provides strength, form setting and is also non-toxic making it ideal for consumables. Tin plating can also be found in paint cans, is used in electronics and is made using a hot dip process.
Rhodium Plating – Less well-known, rhodium is used in the making of jewellery. Rhodium coating prevents tarnishing, is resistant to scratching and gives an attractive lustrous appearance. White gold is often plated with rhodium, as are copper and platinum. The one negative with rhodium is that it isn’t all that strong against wear and tear and may require further coatings in the future to prevent discolouration.
Gold Plating – Gold is desirable for its conductivity and oxidation resistance. Gold plating processes are commonly used in jewellery making and to improve the conductivity of electrical components. Tarnishing can be an issue but this can be rectified by adding nickel.