The U.S. Air Force and aerospace industry now have a more environmentally friendly and lower-cost option to protect a key aircraft system against corrosion.
With support from the Air Force Small Business Innovation Research/Small Business Technology Transfer (SBIR/STTR) Program, ES3 (Clearfield, Utah, USA), an engineering firm specializing in engineering and design of aircraft systems as well as advanced material coatings for aerospace application, has developed a process for plating steel aircraft landing gear components with low hydrogen embrittlement (LHE) zinc-nickel as a drop-in replacement for cadmium.
As a result of this work, there are currently 2,000 landing gear components flying with a LHE zinc-nickel coating.
Low embrittlement cadmium, traditionally used for the past 60 years as a sacrificial protective coating on high-strength steel aircraft landing gear to prevent corrosion, is highly toxic and poses a danger to workers who handle it, as well as to the environment. LHE zinc-nickel is harder, safer, lasts longer, provides better corrosion protection, and costs less when environmental factors are considered. LHE zinc-nickel has been used for other lesser-strength steel applications, such as auto manufacturing, but had not been successfully applied to high-strength steel aircraft landing gear until now.
An LHE zinc-nickel plating line has been installed at Hill Air Force Base in northern Utah, where the 309th Commodities Maintenance Group is using the new method to overhaul an increasing number of landing gear components. Early financial assessments projected the new line would yield a multi-million-dollar savings on hazardous waste disposal.
In addition to addressing legacy systems—a big step because it requires changes to drawings and specifications—LHE zinc-nickel also has the potential to be widely adopted for new aircraft manufacturing.
Source: Air Force SBIR/STTR Program Office, www.afsbirsttr.af.mil.