Session 9: Aerospace/Defense/Military Zinc Nickel Advancements
The following list benefits USAF/ES3 expects from this project:
• Reduce/eliminate the amount of abrasion and galvanic corrosion damage that the HSS landing gear/aircraft components are exposed to.
• Eliminate health exposure concerns of HF acid and meet OSHA emission regulations and reduce the legal liabilities associated with plating, worker safety, and health, disposal (cradle to grave and beyond), etc.
• Cost savings by reducing the amount of condemned landing gear/aircraft components and hazardous waste disposal.
Aerospace / Defense / Military
Advances in Surface Finishing Technology
During the overhaul process of aircraft and landing gear at Hill AFB, various high strength (HSS) aircraft components must have surface plated coatings periodically replaced. Some of those coatings include chromium (Cr), nickel (Ni), cadmium (Cd), and low hydrogen embrittlement Zinc-Nickel (LHE Zn-Ni). To achieve acceptable adhesion properties from the plated coatings, the HSS surface must be activated, and all corrosion/contamination must be removed by grit blast. Additionally, grit blasting, if not done properly, can be abusive to HSS landing gear/aircraft components and contaminated grit can cause galvanic corrosion. After which, some plating process requires that 300M HSS components, which have a higher silica content, have additional activation in an ammonium bifluoride H2SO4/NH4HF2 bath. Phase I Project investigation showed successful surface activation using various surface activation technologies. The two most promising technologies were aqueous cleaning using ultrasonics, with Dipsol LHE Activator and MacDermid MaxPro solutions. Consequently, during this Phase II project, USAF/ES3 completed the research necessary to demonstrate the selected technologies of Dipsol LHE Activator solution and MacDermid MaxPro solutions could replace the current surface activation process as an alternative surface activation technology that would be safer for plating personnel and less abusive to landing gear/aircraft components.