Area of Invention
Materials technology and manufacturing processes

Description of Invention
Environmentally 'friendly' non-chromate technology with performance comparable to chromium bearing coatings

Technology Synopsis
A method and solution used to form a non-chromate conversion coating on an aluminum substrate. The invention was developed to replace the potentially toxic chromic acid process. The method provides a conversion solution capable of substituting a select set of metallic ions for the aluminum ions of the gel formed on the substrate, wherein the metallic ions have ionic radii differing less than 35% of the aluminum ion radii and where the coordination numbers of the respective ions remain the same. The preferred substituting metal ion of the invention is manganese. Manganese was found to be a close match to both the ionic radii and coordination numbers of the aluminum ions to be replaced.

Patent Protection
U.S. Patent 6,248,183, Non-Chromate Conversion Coatings for Aluminum and Aluminum Alloys

Potential Commercial Applications
Provides basis for protecting aluminum and aluminum alloys from corrosion while avoiding environmental problems associated with chromium.

Status of Invention
Technology has been demonstrated at CTC. Licensee would have access to the technical capabilities of CTC, on a fee basis, including chemical processing and coating, process modeling, and process design expertise.