Etching / Deoxidising agent for aluminium and aluminium alloys
Liquid, one component system, acidic solution does not require additions of other acids. Process is fluoride free can be used in immersion or spray applications. Effectively removes oxides and intermetallic residues from aluminium alloy surfaces, especially alloys rich in copper and on some types of forged alloys. Product is used directly after degreasing or alkaline stripping and gives the surface of the parts a white and uniform appearance prior to conversion coating, anodizing or welding.
Features & Benefits
- Meets environmental directives – free from hexavalent chrome
- Not designed to etch surfaces.
- Replaces chromate (Cr+6) based deoxidizing chemistry.
- Enables effective deoxidation, particularly adapted to aluminium alloys, even those with a high copper content
- It retains its properties even when heavily loaded with dissolved aluminium
- Does not require heating for optimum deoxidizing
This process belongs toALUMAL DEOX series
Aluminium has a natural protective oxide surface film and affinity for oxygen, in order to improve the appearance of an aluminium part or component through conversion coating, painting, anodizing or plating processes, requires some additional surface treatment processing to remove the natural oxide layer.
Once aluminium and alloys are exposed to etching solutions, the oxides are often removed but then depending on the alloy of aluminium, there are surface adherent non-reactive reaction products referred to as “smuts” on their surfaces. Desmut formulations are required to remove these from the surfaces of aluminium parts or components. The types of smuts present are related to the alloy of aluminium. For example, 200 series wrought aluminium have resulting copper smuts that are effectively removed by iron based desmut formulations. Alloys containing silicon or magnesium smuts are thoroughly desmutted with blends of acids including fluorides, nitrates & sulphates. All surface smuts must be removed for success with applications of conversion coatings, painting, anodizing or plating aluminium and alloys.
Choices for Anodizing applications include ALUMAL DEOX 411, 436 or 444.
For chemical conversion coating prior to painting, review ALUMAL DEOX 411, 425, 445, or 427.
Coventya offers many additional types of ALUMAL products to effectively deoxidize and desmut all types of cast and wrought alloys of Aluminium. This is just a partial list of what is available; contact your local COVENTYA representative for review of other available technologies.