What is chemical nickel plating?
By means of a chemical process a well adhering amorphous nickel phosphor layer (NiP) is deposited on the metal workpiece / profile. The process takes place without an external power source and is therefore non-electrolytic.
The process liquid consists of a dissolved nickel salt, reducing agent, complexing agents and stabilisers. The nickel salt is the source of the required nickel, the reducing agent initiates the precipitation reaction and is the source of the phosphorus. Complexing agents ensure that the reaction products formed during nickel separation remain in solution. Stabilisers ensure a uniform precipitation rate and prevent spontaneous decomposition of the electrolyte. Once nickel is precipitated the process proceeds automatically, this is called an auto-catalytic process.
The working window of a chemical nickel liquid lies in a certain pH range and temperature, which depend on the type of chemical nickel liquid. The precipitation rates can be influenced by both parameters; precipitation rates are between 10 – 15 µm/hour.
Due to the continuous formation of the reaction products, the chemical nickel liquid only has a limited lifetime. The phosphor component influences the properties of the formed chemical nickel layer in terms of hardness, ductility and corrosion resistance, among other things.