Electroless Nickel Plating Finish Service
Our Electroless Nickel Plating Finish Service enhances part durability, no matter the shape or substrate. From industrial components to precision tools, it adds a hardwearing layer that stands up to tough environments.
- Uniform coverage across complex geometries.
- Boosted corrosion and wear resistance.
- Smooth, consistent surface finish.
What Is Electroless Nickel Plating Finish?
Electroless nickel plating finish, also called autocatalytic nickel plating, is a metal finishing process that deposits a nickel-phosphorus alloy onto surfaces through chemical reactions—no electrical current, rectifiers, or anodes required (unlike electroplating).
The process uses an aqueous solution with metal ions, reducing agents, and stabilizers. Once initiated, the reaction is self-sustaining: the deposited nickel layer acts as a catalyst to keep the plating going, resulting in extremely uniform thickness even on complex shapes (like internal pipe walls or intricate parts). With phosphorus content ranging from 2% to 12%, the finish prioritizes functionality—boosting corrosion resistance, wear resistance, and hardness—making it ideal for industrial components rather than purely decorative use.
Specifications for Electroless Nickel Plating
AMS 2404
- Classes:
Class 1: No post-plating heat treatment, except for processes to relieve hydrogen embrittlement.
Class 2: Heat treatment at 232°C (450°F) or higher to harden the coating.
Class 3: Heat treatment at 191°C (375°F) to enhance adhesion on non-heat-treatable beryllium and aluminum alloys.
Class 4: Heat treatment at 121°C (250°F) to boost adhesion on heat-treatable aluminum alloys. - Grades:
Grade A: Minimum thickness of .001 inches.
Grade B: Minimum thickness of .0005 inches.
Grade C: Minimum thickness of .0015 inches.
MIL-C-26074
- Classes:
Class 1: No post-plating heat treatment, except for hydrogen embrittlement relief.
Class 2: Heat treatment at 232°C (450°F) or above to harden the deposit.
Class 3: Heat treatment at 191°C (375°F) to improve adhesion on non-heat-treatable beryllium and aluminum alloys.
Class 4: Heat treatment at 121°C (250°F) to enhance adhesion on heat-treatable aluminum alloys. - Grades:
Grade A: Minimum thickness of .001 inches.
Grade B: Minimum thickness of .0005 inches.
Grade C: Minimum thickness of .0015 inches.
ASTM B733
-
Types (by phosphorus content):
Type I: No specified phosphorus requirements.
Type II: 1–3% phosphorus.
Type III: 2–4% phosphorus.
Type IV: 5–9% phosphorus.
Type V: 10% or higher phosphorus. -
Service categories (by thickness):
SC0: Minimum thickness of .000004 inches (0.1 μm).
SC1 (Light service): .0002 inches (5 μm).
SC2 (Mild service): .0005 inches (13 μm).
SC3 (Moderate service): .001 inches (25 μm).
SC4 (Severe service): .003 inches (75 μm).
-
Classes (by heat treatment):
Class 1: As-plated, no heat treatment.
Class 2 (Max hardness heat treatment):
Type I: 260°C for 20 hours; 285°C for 16 hours; 320°C for 8 hours; 400°C for 1 hour.
Type II: 350–380°C for 1 hour.
Type III: 360–390°C for 1 hour.
Type IV: 365–400°C for 1 hour.
Type V: 365–400°C for 1 hour.
Class 3 (Adhesion for steel): 180–200°C for 2–4 hours.
Class 4 (Boosting adhesion on carburized steel and age-hardened aluminum alloys): 180 to 200°C, with a treatment duration of 2–4 hours.
Class 5 (Adhesion for aluminum and beryllium): 140–150°C for 1–2 hours.
Class 6 (Adhesion for titanium): 300–320°C for 1–4 hours.
*Select according to your requirements. If you are not sure which specification to choose, please contact us.
Common Types of Electroless Nickel Plating
Low Phosphorus Electroless Nickel
Phosphorus content: 1%–4%
- Key properties: High hardness (58–62 HRc), enhanced wear resistance, temperature tolerance, electrical conductivity, solderability.
- Corrosion resistance: Strong in alkaline environments; poor in acidic. Low compressive stress reduces fatigue failure risk.
- (1-4% P, Type III) Bright to semi-bright; magnetic; strong alkaline corrosion resistance; low stress; 58-62 Rc as-plated; crystalline; suitable for moderate-heavy builds.
Mid Phosphorus Electroless Nickel
Phosphorus content: 5%–9% (most common type)
- Key properties: Moderate hardness (45–57 HRc, 65–70 HRc heat-treated), wear resistance, low porosity for corrosion resistance in alkaline/acidic environments.
- Application-specific ranges: 6–9% industrial, 5–9% electronics, 5–7% decorative.
- (6-9% P, Type IV) Semi-bright to bright; magnetic; good alkaline/acid corrosion resistance; moderate stress; 58-62 Rc as-plated; semi-crystalline; limited to light builds.
High Phosphorus Electroless Nickel
Phosphorus content: 10%–12%
- Key properties: Exceptional corrosion resistance, hardness (45–57 HRc), ductility, stain resistance. Amorphous structure enhances protection.
- Ideal for: Highly corrosive acidic environments (e.g., oil drilling, mining).
- (>10% P, Type V) Semi-bright; non-magnetic; excellent corrosion resistance; low stress; 48-55 Rc as-plated; amorphous; ideal for heavy builds.
Nickel-Boron Electroless Coatings
Boron content: 1–5%
Key properties: High hardness (65–75 HRc as-plated, 80–85 HRc heat-treated), exceptional wear resistance, high melting point, good electrical conductivity and solderability.
Ideal for: High-wear industrial components, electronics (e.g., circuit boards), aerospace parts due to superior hardness and conductivity.
(1–5% B) Semi-bright; magnetic (low boron) to non-magnetic (high boron); strong alkaline/neutral corrosion resistance; moderate stress; 65–75 Rc as-plated; nanocrystalline to amorphous; suitable for high-wear applications.
Properties Comparison Table – Phosphorus Electroless Nickel
[table “281” not found /]
*Note: Phosphorus ranges reflect commercially optimized intervals (not broad theoretical ranges), derived from practical data summarized in our previous projects and targeting stable performance in industrial processes.
