Anodizing

Anodic oxidation ("anodizing") is a process for creating an oxidic protective layer on aluminum or titanium. This process does not actually apply a protective layer on the material, but creates a thin oxide layer by converting the top metal layer.

The conversion is done after chemical preparation (degreasing, corroding) by means of electrolysis. Hydrogen and water are created at the cathode, and aluminum is oxidized to aluminum oxide at the anode. The result is a thin layer of 5 - 25 µm, which ensures good protection against corrosion and wear resistance. Depending on the oxidation conditions and the choice of electrolyte, aluminum alloys of various hardness levels can be created, which can be used for corrosion protection or decorative purposes.

Impreglon products for anodic oxidation

  • CoC®

    CompCote®

    Performance in surfaces

    With its low density (2.8 g/cm3), aluminum, in conjunction with CompCote®, opens up new approaches in technical and decorative applications with increased requirements on quality. CompCote® is a polymer-aluminum oxide composite coating with revolutionary properties.

  • NCA®

    Nucocer® AL

    Electrochemical plasma ceramic coating of aluminum

    Nucocer® AL coatings are produced in plasma-chemical oxidation processes. They have a finely crystallized ?-AL2O3 structure and an amorphous zone in the upper part.

  • NTE®

    Nucotec® EL

    The anodic oxidation of aluminum

    Nucotec® EL layers are made from hard, wear resistant aluminum oxide. They are formed through the chemical reaction that turns aluminum into aluminum oxide.

  • NTH®

    Nucotec® HE

    The hard anodization (hard coat) of aluminum

    Nucotec® HE layers are made from extremely hard, wear resistant aluminum oxide. They are formed through the chemical reaction of the aluminum material in special cooled acid electrolytes.

CompCote® – Performance in surfaces

With its low density (2.8 g/cm3), aluminum, in conjunction with CompCote®, opens up new approaches in technical and decorative applications with increased requirements on quality. CompCote® is a polymer-aluminum oxide composite coating with revolutionary properties. In addition to the CompCote® process, there is also "CompCote®-H". CompCote®-H offers better hardness characteristics and better wear and corrosion properties.

CompCote® is free of heavy metals, fluoropolymers and PVC. The procedure is patented in Europe, the USA and other countries and is classed as food-safe by the American Food & Drug Administration (FDA).

 

Layer structure, layer thicknesses and tolerances

CompCote® is formed by transforming the substrate and therefore guarantees optimal bonding. CompCote® grows in the substrate and out of it too. CompCote® layers are formed through anodic oxidation of the base material and simultaneous molecular bonding of the aluminum oxide layer with polymers. In contrast to the conventional anodization procedure, anodization with the CompCote® process creates a surface with a cellular structure.

Due to the molecular polymer content, CompCote® forms chemical bond bridges when a coordinated top coat is selected. This achieves a better adhesive strength.

 

The optimal solution for your specific application

Examples of applications where CompCote is successfully used:
Architecture, the automotive industry, electrical engineering, photo and video technology, household appliances, hydraulics, information technology, hunting weapons, the food industry, aviation, mechanical engineering, medical technology, pneumatics, sports articles, packaging machines, defense technology

 

Properties

  • High level of corrosion protection
  • High level of wear protection
  • Very good tribological properties
  • Low impact on the surface roughness
  • Protection against cold welding
  • Optimized microstructure
  • Improved surface hardness 300–600 HV depending on the alloy and process
  • High level of fracture strength
  • Good adhesion properties (chemical bonding with top coats)
  • High UV resistance
  • Food safe according to the FDA
  • More lightfast than colored standard anodized layers

 

Hardness & wear protection

CompCote® forms an extremely hard aluminum oxide (1200 HV). However, as with all anodic oxidation layers, only the "apparent hardness" is measured as the layer hardness. This value is between 300–600 HV depending on the alloy and the procedure.

CompCote® is over 3x and around 1.5x more wear resistant than anodic and hard-anodic (hard coat) oxide layers (Taber Abraser Test /MIL A 8625F). Results from the Taber Abraser Test show a significant reduction in the abrasion rate with the CompCote® procedure.

CompCote® replaces chromic acid layers: Thin chromic acid layers (2.0 ?m) are known for their good properties under alternating bending stress, which is why they are used in the aviation industry. CompCote® performs even better in this field, as it has no impact on the alternating bending stress resistance of the base material. It also outperforms chromic acid layers in corrosion resistance tests.

CompCote® is considerably tougher and break-proof: CompCote® shows a fibrous fracture pattern in notch impact tests. Conventional oxidation layers, on the other hand, have a brittle fracture pattern like glass.

In various pairings and friction tests, CompCote® shows very good anti-scuffing properties. In some cases, the friction values even reduce in repeat tests (self-smoothing effect). Stick-slip effects are reduced.

 

Corrosion protection

CompCote® is corrosion-resistant and outperforms conventional anodizing layers in corrosion tests (salt spray test / ASTM B117).

Nucocer® AL – Electrochemical plasma ceramic coating of aluminum

Nucocer® AL coatings are produced in plasma-chemical oxidation processes. They have a finely crystallized ?-AL2O3 structure and an amorphous zone in the upper part.

Main features:

  • High level of hardness
  • Extremely high wear resistance
  • Excellent adhesion to the base material
  • Vibration resistance
  • Good corrosion resistance
  • High temperature resistance
  • Vacuum resistance
  • High absorption of radiation

Application areas

  • General engineering
  • Textile machinery parts
  • Vacuum technology
  • Chemical equipment
  • Lifting technology
  • Drive technology
  • Electrical engineering
  • Aerospace industry
Maximum layer thickness: 300 µm
Standard layer thickness: 70-120 µm
Coating thickness (depending on the alloy): 1200-2000 HV 0.01

Nucotec® EL – The anodic oxidation of aluminum

Nucotec® EL layers are made from hard, wear resistant aluminum oxide. They are formed through the chemical reaction that turns aluminum into aluminum oxide. This results in excellent adhesion to the base material. Nucotec® EL layers "grow" out of the base material by around 1/3 of the layer thickness.

Main features:

  • High quality, decorative surfaces
  • Silky shine to matt etched finish
  • Wide range of colors
  • Good wear resistance
  • Corrosion protection
  • Good dimensional accuracy
  • Food safe

Application areas:

  • Automotive industry
  • Mechanical engineering
  • Photo and video technology
  • Office and data processing technology
  • Pharmaceuticals industry
  • Medical technology
  • Telecommunication
  • Pneumatics
  • Household appliance industry
  • Food industry

 

Nucotec® HE – The hard anodization (hard coat) of aluminum

Nucotec® HE layers are made from extremely hard, wear resistant aluminum oxide. They are formed through the chemical reaction of the aluminum material in special cooled acid electrolytes. The transformation results in excellent adhesion between the base material and the hard oxide protective layer.

Nucotec® HE layers are much more compact than conventionally produced anodic oxidation layers (anodized layers) and are therefore significantly more resistant to wear and corrosion.

Due to the micro-porous properties, only the "apparent hardness" is measured. This value is between 300 – 600 HV0.025 depending on the alloy. The thermal conductivity is around 10% of the base material, the electrical dielectric strength is max. 20 V/µm (Nucotec® HE-Cu and Nucotec® HE-GD) or max. 30 V/µm (Nucotec® HE).

Application areas:

  • Automotive industry
  • Mechanical engineering
  • Aviation industry
  • Electrical engineering
  • Medical technology
  • Food industry
  • Communication technology
  • Measurement and control technology
  • Defense technology

Main features:

  • High, homogeneous hardness
  • Extremely good antiwear protection
  • Good corrosion protection
  • Good sliding properties
  • Excellent adhesion to the base material
  • Good dimensional accuracy
  • High electrical insulation
  • High thermal protection
  • Food safe

The optimal solution for your application

Process type Material (selection) Product example
Nucotec® HE AL AL wrought and cast alloys, e.g. AlMg3, AlMgSi1;, AlMGSiPb, AlZnMgCu, G-AlMg5;, G-AlSi10Mg Precision turned parts, cylinder liners, pump impellers, air bearings, control pistons, pneumatic valves, heating plates, injection molding tools, machine parts
Nucotec® HE-Cu Al wrought and cast alloys with a high copper content, e.g. AlCuMg1, AlCuMgPb, AlCuBiPb, G-AlSi9Cu3, G-AlSi6Cu4, AlCu4Ti Precision turned parts, motor parts, machine parts, rolls, coils, bearing parts, valves
Nucotec® HE-GD Al die-casting alloys, e.g. GD-AlSi9Cu3, GDAlSi10Mg, GD-AlSi12, GD-AlMg9Si Hydraulic cylinders, pump housings, motor pistons, machine parts, coupling parts

Locations for process: Anodizing

Minto

Impreglon Australia Pty Ltd
67 - 77 Airds Road
MINTO NSW 2566
Australia
11 +61 2 9603 2388
+61 2 9603 5253
sales@impreglon.com.au
Local Site

Altdorf

Impreglon Coatings AG
Industriezone Schächenwald
6460 Altdorf
Switzerland
4 +41 41 875 7490
+41 41 875 7297
altdorf@impreglon.ch
Local Site

Třemošnice

Povrchové úpravy Třemošnice s.r.o.
Budovatelů 484
538 43 Třemošnice
Czech Republic
8 +420 469 617 631
+420 469 662 020
info@impreglon-put.cz
Local Site