In industrial automation, failures rarely begin with a dramatic breakdown of an entire machine. More often, the problem arises at a point of contact: a terminal, busbar, connector, or component that has operated for years in humid conditions, under load, and at fluctuating temperatures.
Although a metal surface represents only a small fraction of the entire component, it can determine the stability of electrical conductivity, mechanical durability, and the feasibility of subsequent assembly processes.
This is why electroplated coatings are becoming increasingly important in the manufacture of components for the power industry, electronics, e-mobility, and control systems. Nickel and tin are not merely decorative finishes.
Each coating addresses a different engineering challenge: nickel improves surface resistance to wear and corrosion, while tin helps create durable, conductive connections where bare aluminium would quickly develop an oxide layer.
Nickel Where Durability Matters
Electrolytic nickel plating involves depositing a thin layer of nickel onto a properly prepared metal component. Before the part enters the electroplating bath, it must be degreased, cleaned, and treated to remove oxides and traces of corrosion. Only then can an electric current enable nickel ions to deposit evenly onto the surface.
In practice, nickel plating is selected when a component must operate in an environment exposed to moisture, chemicals, oxidation, or friction.
This applies, among other things, to connectors, terminals, busbars, switchgear components, battery parts, and assemblies used in the automotive industry.
A properly prepared nickel-plated metal component can combine several important properties: higher surface hardness, improved wear resistance, more stable electrical performance, and good adhesion for additional layers.
Nickel may be used both as a final coating and as an intermediate layer before chrome plating, painting, or the application of other technical coatings.
In industrial applications, the thickness of a nickel coating can be selected in accordance with the component’s technical documentation. For copper and aluminium-alloy components, coating thicknesses typically range from 1 to 50 μm.
The difference is significant: a thin coating may provide protection or prepare the surface for further processing, whereas a thicker layer is intended for operation in more demanding conditions.
Aluminium Requires a Different Approach
Aluminium is lightweight, durable, and resistant to many atmospheric factors, but it has one characteristic that complicates its use in electrical engineering: it forms an oxide layer on its surface very quickly. From an electrical-design perspective, this can increase contact resistance and create soldering difficulties.
Tin plating is used in such cases. A tin coating creates a stable surface layer on aluminium that limits the formation of insulating oxides, improves solderability, and helps maintain low connection resistance.
This is particularly important for busbars, connectors, power-distribution components, industrial electronics, and parts used in electromobility.
The process requires extremely thorough material preparation. Aluminium must be degreased, cleaned, and activated in dedicated treatment baths before the actual tin-plating process begins.
Without this preparation, the coating may not achieve adequate adhesion. For further information on tin plating aluminium, including its process and applications, click here.
Two Coatings, Two Functions
The choice between nickel and tin should not be based solely on the type of base metal. The first step is to determine the conditions in which the component will operate and what its surface must achieve.
- Nickel is worth considering for components exposed to wear, oxidation, moisture, and chemical substances.
- Tin is particularly effective where solderability, low contact resistance, and stable electrical connections are the highest priorities.
- Aluminium requires especially careful preparation because its natural oxide layer makes it more difficult to deposit subsequent coatings.
- Copper can be nickel-plated to improve its mechanical and chemical resistance while preserving the properties required in electrical systems.
- The quality of the finished component depends not only on the coating type, but also on surface cleanliness, bath composition, current density, and precise control of coating thickness.
Coating as Part of the Design
In a well-designed automation system, electroplating is not simply a step performed “at the end of production”. It should be considered during component design, material selection, and the definition of operating conditions.
Only then is it possible to determine whether a component requires a harder nickel layer, conductive and solderable tin, or a multi-layer coating system in which each layer performs a different function.
For robotics and automation, the practical benefits are clear: fewer connection-related problems, greater resistance of components to industrial conditions, and more stable operation of equipment that often runs continuously for many years.
