Non - Chromium Conversion Coatings on Aluminium
Abstract
In the current period our efforts were concentrated on the without chromate passivation of Al 2024-T3. This material in known to be very prone to both pitting and intergranular corrosion owing to high Cu content (its composition-4.5% Cu, 1.5% Mg, 0.6% Mn) and heat treatment prehistory (solution heat- treated, then strain-hardened). Corrosion accelerates especially in the presence of halogen ions. The actual mechanism by which the Cl- or F- ions affect corrosion of Al and its alloys is not fully understood, but has been attributed to the interaction between the ions and the protective oxide layer 1,2. The following phenomena are responsible for Al 2024 T3 enhanced susceptibility to corrosion. 1. Enhanced cathodic depolarization. 2. Enhanced permeability of Al oxide layer on the material surface. 3. Galvanic corrosion.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 31, 1997
- Accession Number
- ADA336091
Entities
People
- A. Bodnevas
- G. Rogalsky
- J. Zahavi
- M. Rotel
- O. Berkh