Corrosion is a issue that costs the Army an estimated $3 billion dollars/year according to a study done by the national Bureau of Standards. A major portion of this bill to the Army comes in the form of corrosion of the sheet metal and structural members of all ground vehicles. Metal surface pretreatments such as phosphate coatings play an major role in corrosion prevention. They act as cleaners to the metal and provide a passivated surface for subsequent primer adhesion and corrosion protection. Together with the primer, they offer 75-90% of the total corrosion resistance found on painted sheet metal. Improvements thru the use of advanced metal-phosphate coatings can increase this protection in absolute terms from the current 30-90 hours in a salt spray chamber to 2000 hours. This process in real world conditions equates to an extra 5-10 years of actual service life. Patents on this and related modification of this process to include Mg-phosphate polyelectrolyte have been issued. Continued effort must be pursued to keep abreast of this new and emerging technology to bring it to full commercialization to the DoD community and industry as well.

The objective of this project is to eliminate the use of hexavalent chromium rinses on zinc phosphate and to enhance corrosion protection and adhesion of paint film on ferrous and non-ferrous metal surfaces prior to painting or adhesive assembly.

Technical Approach

Finish the laboratory studies at Brookhaven National Labs (BNL). Transfer this technology to the shop floor at TRW. Validate the concept under actual production on real parts as encountered by industry. Reformulate and adjust process as dictated by the scale up studies. Tasks:

  • Finish the laboratory formulations
  • Conduct scale up studies
  • Move operation to TRW shop facilities
  • Order parts to be pre-treated that are representative of typical automotive assemblies such as doors
  • Conduct pilot plant operations for scale up
  • Reformulate zinc phosphate pre-treatment as necessary to optimize process
  • Paint the door samples at an commercial installation
  • Test sample doors for performances such as corrosion adhesion and durability using standard ASTM or SAE methods
  • Validate the whole production process by writing technical user manuals and cost validation studies
  • Present a technology transfer workshop for DoD and industry
  • Write a final report

This technology will be demonstrated to industry at TRW Inc. in New Jersey on full scale production of parts ranging from large panels to automotive fasteners. We will then write a users manual for the process.


Potential users is all of DoD and industry production that paints ferrous and non-ferrous metals.

Economic Impact: DoD: One time cost avoidance on the Family of Medium Tactical Vehicles is 50,000 trucks x 40 cost avoidance in not using hexavalent chrome rinse is $2,000,000 savings at DoD. For industry based in an annual 10,000,000 production of cars and trucks savings per unit are smaller due to economics of scale is $10/unit the 10 MIL x $10/unit equals $100,000,000 savings annually.