The long-term objective of this project is to replace cadmium plating and its corresponding hexavalent chromium conversion coating with the Low Hydrogen Embrittlement (LHE) Alkaline Zn-Ni coating and a trivalent chromium conversion coating for all high strength and low strength steel parts and components throughout Robins Air Force Base (AFB). The United States Air Force (USAF) will work with Engineering and Software System Solutions, Inc. (ES3) utilizing their (LHE Alkaline Zn-Ni IZ-C17+ plating process and IZ-264 trivalent chromate conversion coating. This effort will demonstrate and validate the ES3 LHE Alkaline Zn-Ni rack plating process and conduct the testing necessary for acceptance of the plating line modifications in the Advanced Metal Finishing Facility (AMFF) at Robins AFB, GA. Several aging cargo aircraft components going through complete overhaul at Robins AFB require part inspection and re-plating. Specifically, these parts include high strength steel fittings with depleted/damaged cadmium plating. The LHE Zn-Ni plating line will allow this work to be accomplished organically and expediently in order to maintain aircraft structural integrity. Examples of these components include C-5 Forward/Aft Ramps and Pressure Doors.

This project will focus on ES3’s Small Business Innovation Research (SBIR) developed rack and barrel plating processes utilizing the Dipsol IZ-C17+ solution, which is a LHE Alkaline plating and IZ264 trivalent chromate conversion coating. The LHE Alkaline Zn-Ni electroplating process is expected to provide superior thermal and corrosion resistance compared to cadmium plating on the proposed cargo aircraft parts. The electroplating process deposits a uniform zinc alloy containing 12-18% nickel and is well suited to cover intricately shaped parts, such as threaded fasteners and components. In addition, the trivalent chromate conversion coating has also proven to perform as good as or better than cadmium with a hexavalent chromium conversion coating. The specific performance issues that require validation for the new plating line in the AMFF include, but are not limited to: fatigue, adhesion, hydrogen embrittlement, corrosion protection, lubricity, appearance, thickness and uniformity.

Expected benefits of implementing the LHE Alkaline Zn-Ni as a cadmium/chromium plating alternative include: 1) Significant reduction and possible elimination of cadmium, hexavalent chromium, and associated cyanide systematically across the USAF and Department of Defense (DoD); 2) Substantial savings by reducing environmental and occupational health compliance costs (e.g. hazmat disposal, indoor air sampling, engineering controls, and Personal Protective Equipment [PPE] upgrades).