Finishing systems for military vehicles require pretreatments that enhance adhesion and provide resistance to corrosion. These treatments either directly contain toxic metals, or require a sealer or other rinse products that do.
To address this issue, Mr. Fred Lafferman and his team at the U.S. Army Research Laboratory demonstrated a zirconium-pretreatment technology as a replacement for existing aluminum and steel pretreatments at military depots.
This provides an alternative to both zinc-phosphate (containing nickel) with chromate post-rinse for ferrous substrates or hexavalent- and trivalent-chromium containing etch-primers and conversion coatings for aluminum substrates.
Demonstrations were conducted at Anniston Army Depot, Letterkenny Army Depot, and at Marine Depot Maintenance Command–Production Plant, Albany.
This advancement increases the sustainability of DoD platforms and reduces risk of exposures to the warfighter and maintenance personnel. Specific benefits from adoption of the zirconium process are (1) the use of a single pretreatment bath optimizes processes for both ferrous and aluminum substrates, reducing the footprint required for pretreatment processing; (2) operations are conducted under ambient conditions for metal-phosphate systems, which greatly limits energy-use when compared to current processes; (3) reduced amount (80%) and toxicity of waste materials generated from conventional pretreatment processes; (4) reduced use of water, further limiting waste production; (5) reduced human exposure to toxic and regulated materials to both warfighters and system maintainers.
Performance testing, including laboratory accelerated corrosion testing and seacoast environmental testing, of the demonstration parts and panels from the three demonstrations have confirmed that the zirconium technology provides performance that is equal to both zinc phosphate and the aluminum conversion coatings. Due to the performance of this technology, we anticipate this will qualify to both TT-C-490, Chemical Conversion Coatings and Pretreatments for Metallic Substrates (Base for Organic Coatings) and MIL-DTL-5541 Chemical Conversion Coatings on Aluminum and Aluminum Alloys. The new type that will be included in MIL-DTL-5541 for non-chrome technologies will be initially reserved for Army assets only. Qualification to these specifications will allow this technology to be transitioned into DoD facilities.
For their efforts in developing less toxic pretreatments, Mr. Fred Lafferman and the U.S. Army Research Laboratory have been awarded the 2017 ESTCP Project of the Year from the Weapons Systems and Platforms Program Area for their project titled Zirconium Oxide Pretreatment for Military Coating Systems.
Project Team:
- Fred L. Lafferman – U.S. Army Research Laboratory
- Daniel Pope – U.S. Army Research Laboratory
- Jeffrey L. Stalker - PPG Industries, Inc.
- Michael F. Baxter - PPG Industries, Inc.
- Lawrence J. Fitzgerald - PPG Industries, Inc.
- Jonathan A. Love - PPG Industries, Inc.
- Brian K. Rearick - PPG Industries, Inc.
