Electroless Nickel is a chemical plating process which, unlike electroplating, does not require electrical current to deposit. Nickel is deposited to the surface metal via an 'autocatalytic' process which deposits the coating in uniform density to the surface being plated.
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 buildups 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 setup. 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
- 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).
- MOULD RELEASE - a good nonstick surface in many applications. Additives such as Teflon or Silicon Carbide can be included into the deposit to further increase the properties such as lubricity and wear resistance.
- Can (like hardchrome) 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.
- ABRASION RESISTANCE can be good to excellent dependent on solution used and hardening processes applied.
- An alternative to STAINLESS STEEL - parts can be manfactured in mild steel and coated with electroless nickel. Provides similar performance at lower cost.
- 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
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 using Electroless Nickel coatings include:
Mining; Oil & Gas; Automotive; Water; Defence & Aerospace; Food*; Electronics; General Industrial.
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)
IMPORTANT INFORMATION FOR METALS ENGINEERS & DESIGNERS
Electroless nickel plating is not a new process. Until recently, it's primarily been busy in the electronics industry. The metal finishing industry worldwide is predicting a huge upsurge in the application of electroless coatings. You need to be informed of the benefits and applications for these coatings or risk being left behind! To start the ball rolling there are links to a number of CASE STUDIES BELOW. If after perusing the information provided here, you still need further information on electroless nickel, we urge you to contact us. Click here to email for additional information on electroless nickel Register for more info.
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Electroless Nickel plating is a process that has many advantages over 'electrolytic
' processes in an engineering environment. The coating can be used in many fields 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 buildups on points, corners, etc.
This process can provide significant savings when comparing to a process such as Hard Chrome
on a complex shape as the article can be machined to shape prior to coating (with an allowance for the plating thickness) and does not require post machining to regain the required precise dimensions. To create an internal coating by electrolytic methods requires the use of complex anode arrangements which are generally costly to produce and setup, with these costs being passed on to the customer. It is also possible to achieve deposits of electroless nickel into internal areas where it would be impossible to use electrolytic methods and is cost competitive over the less satisfactory methods.
(Some of the above information is based on the Nickel Development Institute publication "Properties and applications of Electroless Nickel", Ron Parkinson, December 1997)