Producing precision mechanical parts involves a series of stages and processes, including nickel plating and chrome plating. But which of these two treatments is better? Nickel plating and chrome plating are two distinct methods of modifying the surface properties of metals in different ways. Nickel plating changes hardness and resistance to external factors, making the surface more corrosion-resistant. Chrome plating, on the other hand, coats the material with a layer of chromium for functional or aesthetic purposes.
Nickel plating and chrome plating: how the processes differ
The choice between nickel and chrome plating depends on the specific properties required of the mechanical parts. The decision requires sector expertise, experience and a team of qualified professionals. Let’s start by looking at what nickel plating involves.
There are two main types of nickel plating: electroless (chemical) and electrolytic, which differ in how the nickel is deposited. Electroless nickel plating deposits nickel on various materials using a reducing chemical solution, while electrolytic nickel plating uses electric current to deposit nickel on metal surfaces only. The chemical process can treat materials such as metal, plastic and glass, and can be applied to complex shapes. Electrolytic nickel plating offers high corrosion resistance, which varies with the type of metal and the thickness of the nickel layer.
What is chrome plating for? It serves two main purposes: hard chrome plating and decorative chrome plating. Hard chrome plating adds a layer of chromium of variable thickness to the surface of the part, increasing its hardness and resistance to wear and corrosion. Decorative chrome plating gives a shiny, bright appearance for aesthetic purposes, without improving the mechanical properties of the material.
Experts in precision parts choose between nickel and chrome plating by carefully weighing the advantages and disadvantages of each treatment according to its purpose and intended use.
Hard chrome plating offers high hardness, considerable wear resistance, good corrosion resistance, variable thickness up to over 100 µm and low cost. However, it can be uneven on thick layers and may be limited in some industries. Decorative chrome plating, although inexpensive and ornamental, does not improve the material’s mechanical properties.
Electroless nickel plating is chosen when a uniform layer, excellent corrosion resistance and high hardness are required. However, achieving maximum hardness requires a subsequent heat treatment.