Technology Description

Nanocrystalline cobalt-phosphorus coatings were developed under the SERDP project WP-1152. This technology uses pulse plating to control the nucleation and growth of grains within the coating, creating a nanocrystalline structure. Testing indicated that coating application does not cause hydrogen embrittlement of high-strength steels, which is a significant problem with EHC plating. Performance testing showed that the nCo-P coatings demonstrated superior salt-fog corrosion and pin-on-disk wear behavior compared to EHC coatings, with abrasive wear performance slightly less than for EHC coatings. The nCo-P coatings can be deposited to thicknesses ranging from 0.0001 to 0.020 inches, making them potential alternatives to both EHC and TDC. This technology is a direct drop-in for the existing EHC process and may be incorporated into existing plating lines, although this would require replacement of plating power supplies.

In this project, a 100-gallon nCo-P demonstration plating tank will be installed at Naval Ammunitions Depot (NADEP) Jacksonville and a brush plating system will be installed at Ogden Air Logistics Center (ALC). A demonstration plan, incorporating a joint test protocol (JTP), will be developed by stakeholders. The JTP will include both materials and component tests, utilizing EHC as a baseline. The environmental and cost impact of inserting this technology into repair depots will be evaluated, including implementation, processing and life-cycle costs, and waste reduction. The nCo-P coatings also will be assessed as a replacement for TDC on the ring gear of the Joint Strike Fighter leading edge flap actuator. Other potential TDC replacement applications will be determined.