Anodizing of Aluminum Parts for Small Arms
Navy SBIR FY2008.2

Sol No.: Navy SBIR FY2008.2
Topic No.: N08-114
Topic Title: Anodizing of Aluminum Parts for Small Arms
Proposal No.: N082-114-0335
Firm: Texas Research Institute Austin, Inc.
9063 Bee Caves Road
Austin, Texas 78733-6201
Contact: Rock Rushing
Phone: (512) 263-2101
Web Site:
Abstract: Individual racking of parts during anodization processes is time consuming and inefficient. The objective of this proposed effort is to develop a process that can anodize large number of small parts, fabricated from aluminum alloys, using a non-racking approach while maintaining high surface quality to meet military standards. Two fixture design concepts, batch process and a non-racking fixture, are proposed. In the batch fixture design, ballasts made of porous metal foam are employed to eliminate surface defects due to contacting aluminum parts. The non-racking fixture utilizes highly porous metal foam as the electrical contact to allow maximum electrolyte diffusion, and minimize contact marks. Fixtures are attached to a vibrating axel for maximum agitation, and pulse anodizing methods are applied to achieve better surface finish quality. TRI/Austin will be teaming with two companies to assist in the development of anodizing fixtures and processes. Analytical tests will be conducted to evaluate the anodic film properties including visual appearance, film thickness, Rockwell hardness, abrasion, and corrosion resistance. The results of this research will be an efficient bulk anodizing process that is capable of high volume yield and outstanding surface finish quality.
Benefits: The developed fixture will benefit all types of anodizing processes by efficiently treating a large quantity of parts that vary in shapes and sizes. The fixture design, utilizing highly porous electrical contacts, vibratory agitation, and pulsed power supply, will improve the uniformity, structure, and surface quality of the anodic films. Contact marks occurring commonly in conventional anodizing processes will not be apparent with the new processing technology.