The physical properties of aluminum make it a material commonly used in many industries (transport, building, packaging, beverage cans, etc.).
Physical properties of aluminum :
- Very light metal density = 2.7 (steel = 7.9),
- Colour: metallic white grey,
- Good thermal conductivity,
- Good electrical conductivity,
- Ease of implementation (melting point 660°C).
But aluminum has special chemical characteristics :
- Amphoteric metal: is attacked in both acidic and alkaline environments
- Soluble salts: Al3+, AlO2-
- In a neutral environment: no aggression
- Insoluble salt: Al(OH)3
- Formation in air of a very thin layer of Al2O3 alumina ( 0,01 micron), which plays a certain protective role in a dry and non-aggressive environment.
In order to be used in an aggressive environment, it is necessary to carry out a protective treatment on the aluminum. HENKEL Technologies is at the origin of the formulation of anodic oxidation treatment.
The different processing steps with the BONDERITE® series are :
- Degreasing Alkaline or Acid
- Stripping Satin finishing
- Whitening
- Anodizing
- Coloring
- Sealing
Anodizing consists of coating the aluminum or its alloys with a low oxide layer in order to increase its resistance to corrosion. The benefits of alumina film treatment are :
- Protection against corrosion,
- Protection against abrasion and superficial scratches,
- Mechanical properties,
- Realization of an aesthetic finish (staining),
- Thermal insulation.
