Niplate electroless nickel plating

Electroless nickel plating is a metal coating with high corrosion and wear resistance, applicable to precision machined parts with complex geometries.

A protective film of nickel and phosphorus alloy offering high hardness and chemical resistance, and with high thickness uniformity, is deposited on the surface of the part.

NIPLATE electroless nickel plating treatments are compatible with all the metal alloys commonly used in engineering industry practice. Thanks to its surface characteristics, electroless nickel plating is the go-to treatment for protection of precision machined parts.

The NIPLATE® trademark

To guarantee the quality of our services we created the Niplate® trademark, an EU registered mark owned by Micron Srl, identifying the coatings we supply. The exclusive nature of the trademark allows us to guarantee the highest product and process quality for our customers.

NIPLATE® electroless nickel platings

Brake pistons with Niplate 600 medium phosphorus electroless nickel plating

NIPLATE® 600 – Medium Phosphorus Electroless Nickel Plating

Wear resistance | Corrosion resistance | ISO 4527 NiP(7)

Niplate 600 is a medium phosphorus (5-9% in P) electroless nickel plating. Niplate 600 is the most widely used of all Niplate electroless nickel platings thanks to its high wear resistance, good corrosion resistance, and low cost.

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Pneumatic solenoid valve bodies coated with Niplate 500

NIPLATE® 500 – High Phosphorus Electroless Nickel Plating

Chemical resistance | Corrosion resistance | ISO 4527 NiP(11)

Niplate 500 is a high-phosphorus (10-13% in P) electroless nickel plating. Niplate 500 should be chosen over the other Niplate coatings in the case of food contact parts when high corrosion resistance and protection are paramount. ad agenti chimici aggressivi.

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Tube assemblies of water solenoid valves coated with Niplate 500 PTFE, electroless nickel-PTFE composite

NIPLATE® 500 PTFE – Electroless Nickel Plating with PTFE

Self-lubricating | Non-stick

Niplate 500 PTFE is a composite coating of high phosphorus (10-13%) electroless nickel containing 25-35% of PTFE particles. The coating offers a very low friction coefficient (0.08-0.10), non-stick properties and excellent adhesion to the substrate metal.

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Loom shuttles coated with Niplate 600 SiC, electroless nickel-SiC

NIPLATE® 600 SiC – Electroless Nickel with SiC

Extreme wear resistance

Niplate 600 SiC is a composite coating of medium phosphorus electroless nickel (5-9%) and particles of silicon carbide (SiC) in a concentration of 20-30%. The coating is used for applications in which resistance to abrasive and adhesive wear is of paramount importance.

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Shotgun receivers with Niplate eXtreme coating

NIPLATE® eXtreme – Electroless nickel plating

Excellent corrosion resistance, especially on aluminium

Niplate eXtreme is an electroless nickel plating developed specifically to increase corrosion resistance, especially on aluminium alloys. Can be applied on all aluminium alloys, both from machined billets and from casting.

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The main characteristics of electroless nickel plating

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UNIFORM THICKNESS

Electroless nickel plating produces even film thickness over the entire surface of the part, regardless of geometry.

The entire part is coated, including internal zones, respecting tight tolerances without requiring any masking or reworking.

Film thickness can be calibrated with high precision. Film thickness tolerance is ±10% with a minimum of ±2µm.

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HARDNESS AND WEAR RESISTANCE

Electroless nickel plating features exceptional hardness, superior to almost all other metal alloys.

Heat treatments performed on electroless nickel platings make it possible to increase hardness and wear resistance properties greatly, achieving hardness of 1000 HV (69 HRC), i.e. more than case hardened or nitrided steel. This makes it possible to increase the wear resistance of plated components significantly, thanks also to the low friction coefficient of electroless nickel platings.

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CORROSION RESISTANCE

Electroless nickel plating provides corrosion protection by forming a sealed barrier layer that isolates the part from aggressive external agents.

Electroless nickel plating offers high chemical resistance in multiple aggressive environments, including in the presence of hydrocarbons, or neutral, alkaline, or slightly acidic saline solutions.

Depending on the coating applied and the substrate material, corrosion resistance values of more than 1000 hours NSS (Neutral Salt Spray test) can be achieved.

Aesthetic appearance

Electroless nickel plating has a bright metallic appearance with a stainless steel-like colour.

It features excellent oxidation resistance and thus maintains its colour and lustre through time.

The surface morphology of the part and its surface roughness are not affected by the coating so the final aesthetic appearance will reflect the starting appearance. A matt finish can be obtained by means of sandblasting, shotblasting, or grit blasting.

Nickel plated solenoid valve spools

Coatable metal alloys

Electroless nickel plating can be applied to the majority of alloys commonly used in mechanical engineering practice.

The characteristics of the alloy do not affect the coating characteristics because electroless nickel plating involves the deposition of a nickel-phosphorus alloy coating on the surface of the part.

By adopting certain measures, the process can be applied to substrates that have undergone thermochemical treatments such as case hardening and nitriding, and to stainless steels.

  • Carbon steel
  • Stainless steel (e.g. AISI 304, 316, 420, …)
  • Case hardened and/or nitrided steel
  • Machined billet aluminium alloys
  • Cast aluminium alloys
  • Copper alloys (brass, bronze, copper-beryllium, …)
  • Titanium alloys

Certifications and reference standards

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PRODUCT TECHNICAL STANDARDS

  • Conformity with ISO 4527 Autocatalytic Nickel-phosphorus alloy coatings
  • Conformity with ASTM B733 Autocatalytic Nickel-Phosphorus Coatings on Metal
  • Conformity with other standards MIL-C-26074, AMS C26074, AMS 2404
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CHEMICAL SAFETY

  • REACH conformity, compliance with regulations on contents of SVHC (substances of very high concern)
  • RoHS conformity, compliance with regulations on contents of metals subject to restriction
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FOOD CONTACT

  • Certification to NSF-51, the standard that defines the minimum hygiene and protection characteristics of materials employed in the manufacture of food contact components and equipment
  • Conformity with GMP – Reg. (EC) 2023/2006 on good manufacturing practice
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MANAGEMENT SYSTEMS

  • ISO 9001 quality management system certification
  • Conformity with CMRT and CRT, no use of minerals from conflict zones
  • Conformity with the IPPC environmental directive

The electroless nickel plating process

Electroless nickel plating is a process of nickel-phosphorus alloy deposition on metal parts. It is performed by dipping the parts in treatment solutions in accordance with defined phases, which differ for different metals, including degreasing, deoxidizing in alkaline and acid solutions, surface activation, and nickel plating.

The nickel is deposited without the use of electric current, by means of a redox reaction between the cation Ni2+ from nickel sulphate and the anion H2PO2- originating from sodium hypophosphite (reducing agent). This makes it possible to create a uniform and calibrated coating over the entire surface of the part, regardless of its geometry.

With the aim of improving the surface properties of electroless nickel platings, functional particles can be deposited within the electroless nickel matrix. An example of this technique can be seen in Niplate 500 PTFE with co-deposited PTFE particles, which impart surface smoothness and a low friction coefficient, and in Niplate 600 SiC with co-deposited silicon carbide particles, which produce extremely high hardness and wear resistance values.

Unlike other companies in the sector, Micron uses its own treatment solutions, developed through the years thanks to our detailed understanding of nickel plating chemistry and process. This allows us to guarantee coatings of enduringly high quality through time.

Differences between electroless nickel plating and electrolytic coatings

In electrolytic processes (also called galvanic processes), such as chrome plating or electrolytic nickel plating, electric current is used for the metal coating deposition process. The applied current tends to discharge following the path of least resistance. Consequently, coatings tend to be thicker on the outer surfaces and corners of the parts, and thinner or even completely absent on internal zones, especially in the case of parts with complex geometries.

Conversely, electroless nickel plating has the significant benefit of being able to coat the entire surface of parts evenly, even in the presence of complex geometries, including internal zones. This allows compliance with dimensions with tight tolerances, avoiding the need for masking or reworkings after the treatment.

Point effect with tendency of electrolytic coatings to increase in thickness
ELECTROLYTIC COATINGS
Uniform and constant thickness over the entire electroless nickel plated surface
ELECTROLESS NICKEL PLATING