A Comparison of the Capability of Sensitivity Level 3 and Sensitivity Level 4 Fluorescent Penetrants to Detect Fatigue Cracks in Various Metals

by National Aeronautics and Space Administration

In April 2008, NASA-STD-5009 established a requirement that only sensitivity level 4 penetrants are acceptable for NASA Standard Level liquid penetrant inspections. Having NASA contractors change existing processes or perform demonstration tests to certify sensitivity level 3 penetrants posed a potentially huge cost to the Agency. This study was conducted to directly compare the probability of detection (POD) of sensitivity level 3 and level 4 penetrants using both Method A and Method D inspection processes. POD demonstration tests were performed on 6061-Al, Haynes 188 and Ti-6Al-4V crack panel sets. The study results strongly support the conclusion that sensitivity level 3 penetrants are acceptable for NASA Standard Level inspections. Parker, Bradford H. Goddard Space Flight Center CRACKS; DETECTION; FLUORESCENCE; PENETRANTS; SENSITIVITY; FATIGUE (MATERIALS); METALS; COSTS; PROBABILITY THEORY; ALUMINUM ALLOYS; TITANIUM ALLOYS; VANADIUM ALLOYS; INSPECTION; DATA PROCESSING; METALLOGRAPHY

46 pages, Paperback

Published May 22, 2018

About the author

The National Aeronautics and Space Administration (NASA) is an independent agency of the U.S. federal government responsible for the civil space program, aeronautics research, and space research.