An In-Situ Repair System for Stress-Induced Fatigue Cracks in Aircraft Metal Parts Based on Electrochemical Deposition

Throughout the aviation world, military and commercial operators face the serious danger of metal fatigue fractures. The FAA has identified these risks as widespread and significant. Additionally, the advanced age of many aircraft fleets, including in the U.S. Air Force, which has an average age of nearly 30 years with 8 fleets averaging over 50 years, further exacerbates these hazards. The need for effective, preventative treatments has never been greater. Technical Abstract: This proposal, for SBIR D2P2 funding of an An In-Situ Repair System for Stress-Induced Fatigue Cracks in Aircraft Metal Parts Based on Electrochemical Deposition, seeks to build upon nearly 10 years of research to provide a revolutionary treatment approach. This treatment can arrest fatigue crack growth, prevent cracks from forming, and theoretically extend indefinitely the lifespan of treated metal components. In laboratory testing, the treatment arrested further crack growth for between 2,000 and 230,000 testing cycles and extended the fatigue life of components by 10%-60%. The treatment also provides corrosion resistance, with treated steel specimens exhibiting an 80% reduction in corrosion compared to non-treated samples in a 12-week simulated seawater exposure experiment. Finally, a mathematical model developed as part of the research allows for accurate prediction of fatigue arrest duration, allowing effective scheduling of maintenance.