Author: Nathan Hughes
Phone: (801) 775-2270
Cadmium is a soft metal used as a thin corrosion inhibiting coating on steel parts such as landing gear and missile ground systems shock isolators overhauled at Ogden Air Logistics Complex (OO-ALC). Cadmium was originally specified for these systems due to its excellent corrosion inhibition qualities, lubricity, ease of application, and ease of removal.
Cadmium has been defined as a human carcinogen by the International Agency for Research on Cancer and the US National Toxicology Program and the process for electroplating cadmium requires the use of large amounts of cyanide. Since the 80’s the Air Force has sought replacements for cadmium plating and was successful at eliminating cadmium from lower strength steels processed at Robins Air Force Base (AFB) (in the 80’s) and Tinker AFB (in the 90’s). However, these formulations degraded high strength steels and were not suitable for applications such as landing gear.
In 2007, the OO-ALC cadmium replacement team lead efforts, in coordination with commercial partners, to develop and test LHE Zn-Ni; a new non-proprietary, environmentally friendly corrosion preventative for high strength steel. Testing was extensive and included corrosion, fatigue, hydrogen embrittlement, coating adhesion, paint adhesion, and torque tension, among others. These tests were conducted alongside cadmium control samples. The LHE Zn-Ni samples performed “as good as or better” than cadmium in nearly all cases. In addition, this process can be implemented with no form, fit or function changes, no operational changes to component and has the benefit of a net cost savings.
By 2011, the LHE Zn-Ni had passed the initial tests and a full-scale prototype LHE Zn-Ni line was installed at OO-ALC (Bldg. 505) in 2012.
From 2012 to 2013, the full scale prototype line went through additional verification and testing. LHE Zn-Ni plating of production landing gear components began in June 2014. OO-ALC is working to eliminate cadmium plating as quickly as they can and plan to more than double their LHE Zn-Ni plating capacity during the next few years.
Currently, OO-ALC has the only successful LHE Zn-Ni plating line for high strength steels in the Department of Defense, leading the effort to replace/eliminate cadmium plating on high strength steels.