Project Number: A2929

Project Title: Enhanced Wear Coating for Protection of Turbofan Components

Period of Performance: JAN23 – JUL25

The Center for Naval Metalworking (CNM) in partnership with Pratt & Whitney (P&W) are seeking a viable alternative wear coating to the current electroless nickel-B coating to improve wear performance in F135 engines on wear-sensitive parts with a lower cost, low internal stress, columnar structure electroless nickel-P coating with significantly greater process control. Baseline coating is today's preferred coating solution for its high hardness, wear resistance, low internal stress, and low fatigue debit. P&W had considered a lower cost alternative to current baseline Ni-B coating, with a high nickel-phosphorus (P), laminar structure coating. The high nickel-P coating is manufactured via a more conventional electroless nickel-P (EN) process and is attractive because of its lower cost, greater process control, and wide acceptance in the aerospace industry. However, while it is capable of providing similar wear protection as the baseline nickel-B coating, it exhibits up to 75% fatigue debit on titanium alloys. Due to the fatigue debit, it prevents it from being applied to military engine parts, specifically the fatigue limited F135 engine parts. The key contributor in fatigue debit is the structural difference between the baseline electroless nickel- and conventional electroless Ni-P. The more conventional EN coating process yields a laminar grain structure resulting in higher internal stresses and increased stress to the substrate (part), thus decreasing part fatigue life. This high internal stress in the coating generates many through coating cracks. These cracks act as crack initiation sites bringing down the cracking stress of the coated alloys and generating significant fatigue debit.

The project team will develop a new chemistry, utilizing both nickel-P and a columnar structure, and procedure to disseminate to industry and increase the U.S. wear coating supply base to mitigate schedule delays, reduce cost, and improve performance on the current wear coating for nickel and titanium base aerospace alloys. The anticipated period of performance for the project is January 2023-July 2025.

By reducing the total coating cost by approximately 20% per part, P&W estimates that this CNM effort may result in five-year savings of approximately $7K for each F35. The five-year return on investment for the project is anticipated to be 1.78:1. 

Assuming all performance metrics meet P&W product requirements and cost savings are confirmed, the new coating will be applied to every part possible on the F135. Initial estimates predict 180+ parts will be affected by this new coating. Upon successful and timely completion of the Enhanced Wear Coating project and acceptance of both the technology and associated business case by the acquisition Program Offices, P&W will begin the process of qualifying multiple coating and chemistry suppliers to develop a larger industrial base expediting the coating process. P&W anticipate partial implementation in the first quarter of fiscal year 2025.