materials-finishes

Black Nickel Electroplating: Sulfur Chemical Immersion and Sealant Layers

Engineering Overview: Process breakdown of Black Nickel electroplating on brass lock cylinders, detailing nickel-zinc-sulfide alloy deposition and protective clear coats.

Technical & Engineering Specifications

Substrate Solid H59 Extruded Brass
Salt Spray ASTM B117 144 hours
Application Modern Architectural & High-End Residential
Finish Code Black Nickel / Gun Black
Plating Stack Bright Nickel (12um) + Black Ni-Zn Strike (1.5um) + Lacquer

Black Nickel Chemistry

Black Nickel (BN / Gun Black) delivers an elegant deep metallic black finish with gunmetal undertones, distinct from matte powder coats.

Electroplating Process

  1. Bright Nickel Base: 12 μm standard bright nickel base layer for corrosion resistance.
  2. Black Nickel Alloy Strike: Electroplated from a specialized bath containing nickel sulfate, zinc sulfate, and sodium thiocyanate, depositing a thin metallic Nickel-Zinc-Sulfide alloy layer.
  3. Thermosetting Lacquer: Sealed with baked clear polyurethane lacquer to provide ASTM B117 salt spray endurance of 144+ hours.

Frequently Asked Engineering & Selection Questions

Q1: What gives black nickel its distinctive metallic black color?

A co-deposited alloy of nickel, zinc, and sulfide plated over a bright nickel base, sealed with clear lacquer.