Rhodium plating: everything you need to know

Rhodium plating, an aesthetic treatment and corrosion protection for metals

When we see an object in gold or silver and admire its shine and brilliance, this is partly attributable to a particular technique called rhodium electroplating.

This surface treatment works through electrolysis using a rhodium salt (which gives it its name). Rhodium is a precious metal that belongs to the platinum family.

Rhodium plating is therefore used to make metals harder and more resistant and it is widely used, in fact, for jewellery. Through this process, gold and silver acquire greater value without affecting their physical properties. A clear example is white gold, which would not have its characteristic shiny white colour if it were not rhodium-plated.

The rhodium electroplating process

Rhodium plating involves the immersion of gold, silver or a non-noble metal in an electrolytic rhodium bath. Electricity is applied and a very thin layer of rhodium imperceptible to the naked eye (ranging from 0.1 to 25 microns thick) forms on the surface, forming a very bright, resistant film.

In this way, rhodium-plated metals acquire particular shine and are able to resist wear and non-aggressive chemical agents over time. Abrasive products should not be used for cleaning.

Impreglon uses a series of techniques similar to rhodium electroplating to protect metal surfaces, giving them corrosion protection. These consist of the coatings in the TempCoat® (polymer and fluoropolymer coatings) and Halar® systems, which, in addition to guaranteeing corrosion protection and abrasion resistance, also provide electrical insulation.