|Acquisition Program: ||PMA-265 F-18 Hornet, Super Hornet & Growler Program|| Objective: ||Develop non-chemical stripping technologies and processes to remove chrome from F-18 landing gear without machining and/or damaging base materials.
|| Description: ||Hard chrome plate is used extensively to provide wear and corrosion resistant surfaces on landing gear and hydraulic actuators. Current processes for reworking worn surfaces require the use of chemical baths to strip the chrome plating. These baths can introduce hazardous waste to the environment through four different ways – airborne pollutants during operation, bath drag-out to rinse water as the parts are removed, bath dump after chemical activity is reduced and accidental spillage. While every precaution is taken to minimize environmental hazards and to recycle chemicals to reduce the waste stream, a non-chemical means of stripping hard chrome plate is highly desirable.
Innovative, non-chemical approaches for stripping hard chrome plate are sought. The proposed process should be cost-effective and without risk of damage to substrate materials, which are typically low alloy steels or even stainless steel. The process should be able to clean surfaces where the coating is unevenly worn or even spalled. Chrome plated areas are usually adjacent to critical features, such as corner radii or bearing faces, which must not be damaged in the stripping process. Ideally, the process would also be suitable for stripping high velocity oxygen fuel (HVOF) coatings, which are increasingly being used as an alternative to hard chrome plate. The process must be suitable to non-flat geometry, such as struts and inner diameter bores as small as 2” diameter. No heat should be generated during the removal process and no material is to be removed from the substrate during the process. Portability of the process is a plus and chrome removal rate should be short enough, not causing a burden to the fleet/depots.
|| ||PHASE I: Demonstrate the feasibility of the proposed process by stripping hard chrome plate from six flat sample coupons and six round coupons. The plating must be done in accordance with AMS-2460 and the surface must be characterized before plating and after stripping. Sample characterizations and stripped coupons are to be sent to the Navy for evaluation. Perform a cost analysis comparing the proposed process to current chrome stripping methods.
|| ||PHASE II: Demonstrate the suitability of the process for stripping actual landing gear components. Explore the ability of the process to strip HVOF coatings. Build and demonstrate a prototype unit suitable for operation at a Navy repair and overhaul facility.
|| ||PHASE III: Fully develop the chrome stripping processes/units and transition for Navy or other government use.
PRIVATE SECTOR COMMERCIAL POTENTIAL/|| ||DUAL-USE APPLICATIONS: Successful development of this technology could be transitioned to commercial airlines for the removal of chrome.
|| References: ||
1. McClay, W. J., & Reinhard, F. P. (2007). Waste Minimization and Recovery Technologies” Metal Finishing, 105 (10), 715-742.
2. Legg, K. (2008). Proceedings from ASETS Workshop: “Surface Finishing and Repair Issues For Sustaining New Military Aircraft”. Tempe, AZ.
3. AMS 2460 - Plating, Chromium|
|Keywords: ||Chrome; Chrome Removal; Landing Gear; Plate; Stripping; Coating|