| About this Abstract |
| Meeting |
2020 TMS Annual Meeting & Exhibition
|
| Symposium
|
Coatings and Surface Engineering for Environmental Protection II
|
| Presentation Title |
The Effect of Surface Treatment on the Performance of a Zirconium-based Conversion Coating on AA7075 Automotive Alloys for Protection Against Filiform Corrosion |
| Author(s) |
Carol F. Glover, Mary Lyn Lim, John R Scully |
| On-Site Speaker (Planned) |
Carol F. Glover |
| Abstract Scope |
The resistance to filiform corrosion (FFC) of AA7075 automotive aluminum alloys, when pretreated with a Zirconium-based conversion coating, was investigated as a function of surface-treatment and heat-treatment. Specimens were prepared with two surface-treatments, (1) alkaline-cleaning and (2) alkaline-cleaning and subsequent acid deoxidation. These were compared to a control and studied with and without a pretreatment. Two different heat-treatments were applied to mimic curing temperatures. Data from FFC and full-immersion corrosion experiments are compared with surface characterization data to study the FFC kinetics and inhibition mechanism of the FFC process. The effect of surface-treatment and heat-treatment on intermetallic particle (IMP) density and surface enrichment of alloying elements is discussed. It was found that specimens prepared by alkaline cleaning-only provided superior resistance to FFC and this performance was shown to be least effected by the applied heat-treatments. A substantially thicker (60 nm) Zr-based oxide layer was shown to form on this specimen. |
| Proceedings Inclusion? |
Planned: Supplemental Proceedings volume |