Electroless Nickel, Alodine &
Chrome on Aluminium

Electroless nickel is deposited uniformly without electrical current through chemical reduction – achieving ±1 µm thickness precision even in bores, deep channels and complex 3D geometries. High-phosphorus (>10 % P) Ni-P offers excellent corrosion resistance; medium phosphorus optimises wear and hardness.

After heat treatment (300 °C / 1 h) hardness rises from HV 500 to HV 850–1,000. Suitable for steel, aluminium, copper, titanium and – with special activation – plastics. Standard: DIN EN ISO 4527 / ASTM B733.

Alodine (chromate conversion coating) is a chemical conversion layer for aluminium and aluminium alloys – 0.5–1 µm thin, dimensionally neutral. Two functions: (1) corrosion protection and (2) adhesion base for paints, primers and adhesives.

REACH-compliant Cr+3 version (clear/green) and classic Cr+6 version (yellow) available. Electrical conductivity retained – critical advantage for aerospace grounding requirements. Standard: MIL-DTL-5541 / EN 2437 / AMS 2473.

Aluminium is not suitable for direct chrome plating, as the aluminium oxide layer prevents adhesion. Solution: zinc immersion (zincate) → copper or nickel interlayer → chrome. The multilayer system preserves aluminium's low weight while providing the surface hardness and corrosion resistance of chrome steel.

Typical layer sequence: Al → zincate → Ni (10–25 µm) → Cr (0.1–1 µm). All process steps at Innox-Engineering under one roof. Main applications: automotive, aerospace, consumer electronics.