Zinc plating is a metalworking process in which an outer protective layer of zinc is applied. But why is it so important, and what exactly is it for? Let’s find out.
Zinc plating protects and strengthens metals against corrosion from external agents or wear over time, such as rust. The zinc plating process prevents micro electrolytic cells with anodic action from forming in the metal. Zinc is perfect for this because it is less electronegative than steel and can therefore prevent corrosion by protecting the underlying metal.
All types of zinc plating: hot-dip, cold and electrolytic
There are several types of zinc plating, the most common being hot-dip, cold and electrolytic. What are the differences, and why choose one over another?
Hot-dip galvanising applies the zinc coating hot: the metal is immersed in a bath of liquid zinc at 450°C. Cold galvanising, on the other hand, applies the zinc coating cold, as a paint based on synthetic resins loaded with zinc. Cold galvanising is clearly less protective than hot-dip, but for materials that are difficult to process it is a useful option to consider.
Electrolytic zinc plating, also called galvanic zinc plating, involves immersing a material in an electrolytic solution containing zinc salts. Compared with hot-dip or cold galvanising, it is ideal for protecting precision components.