The DURNI-COAT® process consists in electroless deposition without any external source of electricity. In this process the workpiece is immersed into an aqueous process solution with a specific content of nickel ions. During the process these ions are reduced into metallic nickel. The chemical reacting agents and formulators of the electrons required in this process are the hypophosphite ions in the solution. These agents are transformed, by oxidation in the course of the reaction, into orthophosphite. A nickel-phosphorus alloy layer forms on the workpiece’s surface. This layer effectively protects the workpiece against wear and corrosion.
DURNI-COAT® is ideal for the functional coating of metals and plastics. The properties of the Electroless Nickel layer range from chemical resistance, dimensional accuracy, excellent anti-friction behaviour, electrical conductivity to outstanding hardness. In addition, DURNI-COAT® ensures uniform layer formation true to the original contours. The layer is the ideal solution for the plating of even geometrically complex workpieces with sharp edges and impressions, accessible cavities or bores.
DURNI-COAT®’s wear and corrosion resistance depends on the layer’s phosphorous content. This content can be increased or reduced depending on the electrolyte’s composition and it can be varied under specific process conditions. Even the layer thickness affects the coating’s resistance: layers with a thickness in the 2 to 10 μm range are resistant to mild corrosion loads, while those in the 5 to 10 μm range are resistant to mild wear loads. A moderate degree of resistance requires layers with a thickness in the 10 to 25 μm range, while severe and very severe loads require thickness values ranging from 25 to 50 μm and over 50 μm respectively.
Electroless Nickel DURNI-COAT® can coat almost any metal:
- All low-alloy ferritic steels
- Cast iron-based materials
- Stainless steel
- Non-ferrous metals (copper, brass, …)
- Aluminium alloys
- Die-cast zinc
- Titanium-based materials
- Sintered metal materials
Other metal and ceramic materials can also be coated after performing trials on samples.