Electroless nickel – when accuracy is everything

 

 

Contour and dimensional accuracy are the most important properties of the functional electroless nickel surface, also known as nickel phosphorous (NiP). These properties make the plating process ideal for components with complex geometries as well as for a wide range of applications common in the automotive sector, the electrical industry and mechanical engineering.

Description of the process

Electroless nickel or nickel-phosphorus is an alloy layer of nickel and phosphorus deposited without the use of an external electric current. Electroless nickel plating is mainly used for functional applications, as it is extremely hard and wear-resistant. However, the two properties hardness and wear resistance are contrary to each other, which means that the phosphorous content needs to be specifically adjusted to suit the requirements of each layer and component.

The electroless nickel layer is deposited without the need for an external electric current. The process ensures outstanding contour and dimensional accuracy due to the extremely evenly distributed layer thickness on practically all metals and alloys. For this reason, autocatalytically generated nickel coatings are a very good solution for components with complicated geometries and even interior coatings can be implemented to a certain extent using this process.

Part with electroless nickel plating

Electroless nickel is good solderable

Part with electroless nickel surface

Holzapfel Group offers electroless nickel coatings in a great variety.

Properties of electroless nickel plating

Electroless nickel coatings are not only extremely accurate in terms of size and contour, they are also very wear-resistant, i.e. the surface offers long-term protection against wear as well as corrosion and also provides a high level of conductivity. The high-phosphorous version of electroless nickel, i.e. with a phosphorous content over 10%, is not magnetic.

Electroless nickel with varying phosphorous content

Electroless nickel is usually available with low-, medium- and high-phosphorous concentrations. The percentage of phosphorous in the electroless nickel coating is largely responsible for the properties of the coating. Phosphorous concentrations of approx. 9% provide a high level of corrosion protection. The lower the percentage of phosphorous in the nickel-phosphorous alloy (NiP), the higher the wear protection. The level of hardness can be further improved (up to 1,000 HV) by adjusting the phosphorous content accordingly.

Further detailson electroless nickel and case study

  • Here you can read more about a specific application with particularly good solderability of electroless nickel coatings, e.g. for cooling plates, brake and control systems, or for use in heat sinks (electrical industry, electronics) and casings