The Electro-less Nickel plating process has many advantages over 'electrolytic' processes in an engineering environment. The coating can be used where a hard, corrosion resistant finish is required.
A major advantage of the process is that it is possible to coat the whole surface of an item EVENLY, including internals, unlike electrolytic processes which have difficulty depositing into recessed and internal areas and can result in excessive build-ups on points, corners, etc.
This process can provide significant savings when comparing to 'Hard Chrome' (an electrolytic process). To create an internal coating by electrolytic methods requires the use of complex anode arrangements which are generally costly to produce and set-up. With Electroless nickel, the coating will not distort the dimensions. Normally the item is machined with allowance for a coating thickness and not require post machining to regain the required dimensions (as hard chrome would require).
Benefits/Advantages of Electroless Nickel Plating:
- UNIFORMITY of coating ensures threads, holes, recesses and internal areas all receive the same amount of plating as sharp corners, edges, flat surfaces and high points. The coating can also provide resistance to a range of chemicals.
- Electroless Nickel coatings can provide WEAR RESISTANCE and CORROSION PREVENTION.
- LUBRICITY - it is able to slide over other metal surfaces without galling (reduces wear, increases service life).
- Can (like hard-chrome) be machined. However, THE REQUIREMENT TO MACHINE BACK TO TOLERANCES IS OFTEN ELIMINATED by the ability to apply the nickel coating uniformly and in thicknesses that can maintain tolerances to within approx 10 mil.
- HARDNESS - varied solution types can give a variety of as plated hardness. Heat treatment increases the hardness to a maximum of approx. 70 Rockwell C
Applications of Electroless Nickel Plating: Valves, tubulars, heat sinks, shafts, drilling equipment, rollers, dies & moulds, tooling, pumps, hardware & more. Wherever there is need to prevent corrosion, reduce wear or improve hardness and durability.
Industries: Mining; Oil & Gas; Automotive; Water; Defence & Aerospace; Food*; Electronics; Gen. Industrial.
Design Cautions: Consider all surfaces of the item. Allow for an even surface tolerance. 'Selective' coating (of only some surfaces of an item) is possible via masking of selected surfaces, however this will affect cost. Be as clear as possible about the surface quality and outcomes you expect in the finished product. Consult your finisher in relation to metal substrates this process is suited for. (*May not be suited to some food processing applications)