Electroless Nickel

Plated coatings tend to over-plate on corners and edges due to the nature of electrical fields. The electroless method of applying coatings ensures completely even deposits, no edge build-up, excellent corrosion protection and creates a low friction surface. Our high phosphorous Electroless-Nickel provides the high corrosion resistance and the ability to age-harden the layer from 48 – 50 HRc (as-plated) to ~68 HRc. Typical coating thickness of 8-12 µm, although other thickness is available on request. 

The higher phosphorus E-Nickel coatings have the advantage of:

  • Low friction (vs steel: 0.38- dry, 0.21 – lubricated)
  • Lower porosity (i.e. improved corrosion resistance)
  • Non-magnetic
  • Low thermal expansion
  • High corrosion resistance
  • Tightly follows all contours and recesses with no over-plating on edges and corners

 

Composite E-Nickel Coatings

Composite E-Nickel is e-nickel plated together with fine particulates such as Teflon, Silicon Carbide, Boron Nitride or Diamond, and  gives the coating unique properties.

Our Metal Teflon Coating (MTC) coating is an E-N coating with embedded Teflon/PTFE particles which gives a hard, very low friction surface with non-wetting properties. This is particularly important for the plastics industry where it is assists in release and flow for complicated mould designs incorporating ribs and recesses. Plastic moulders have reported reduction in cycle time of between 4-8% using MTC. It is also used very succesfully on parts requiring a durable, dry running, low friction surface such as feeders, slides and shafts. MTC further has the advantage of a constant friction coefficient under a wide range of loads. Due to the electroless nature of the coating, internals and difficult geometries are easily coatable.

This coating is typically 10-15 microns in thickness and can be applied to steel, stainless, aluminium and copper.  A uniform plating thickness develops wherever the solution contacts the part. Grooves, slots, threads and even the inside of tubing plates evenly.

Should a temperature resistance of more than 300°C be required, the Teflon can be replaced with Boron Nitride. The E-N/BN coatings have successfully been used to enhance release properties in complex moulds and offer moderate wear resistance, excellent lubricity and release properties which outperforms most other coatings.

Electroless Nickel can also be infused with Silicon Carbide. As the SiC is a very hard substance, it significantly improves wear resistance and it is an effective competitor to chrome plating, but without the limitiations of chrome plating with regards to edge built up and limited throwing power. 

Wear Testing

ref: Electroless Nickel Composite Coatings, Advanced Materials & Processes, May 2008 – find this excellent article in our downloads