Improvement of Corrosion Resistance of Aluminum Alloy by a New Surface Treatment Technology ‘PAHP-Treatment’

“PAHP-Treatment” is a new surface treatment technology that improves the corrosion resistance of a painted aluminum-alloy part and has only a low impact on our environment. Moreover thanks to this technology, we can significantly save our cost. PAHP-Treatment is an abbreviation for “Phosphoric Acid and Hydrogen Peroxide” and one of the surface preparations that above both are applied. As aluminum element of the surface of a part rusts when being soaked in a corrosion environment, the adhesion of a material and its painting decreases. But such aluminum oxide is almost removed from there by this PAHP treatment, and then, the surface becomes rough. As a result of it, the adhesion between the surface and its painting is improved. Therefore this treatment was applied to the painted parts of our outboards (Photo. 1) that require the higher corrosion resistance because they are used under a lot of severe conditions and has been adopted in aluminum-alloy pretreatment process.