An Improved Anodizing Practice for Aluminum Bumpers

The paper describes a cooperative investigation by Alcan International Limited, Douglas & Lomason Co, and Ford Motor Co. into improving bright anodized finishes and particularly the prevention of the yellow tinge sometimes found on anodized aluminum bumpers. It gives an account of the work done in the determination of yellow tinge intensity and abrasion resistance associated with different anodizing conditions, leading to the final selection of an optimum practice. It includes the subsequent verification in production plant trials as well as approval testing by Ford culminating in a revised manufacturing process specification PL52-03 to reflect this improved practice.