Role of plastic work in fatigue crack propagation in metals

✍ Scribed by Y. Izumi; M.E. Fine

• Publisher: Elsevier Science
• Year: 1979
• Tongue: English
• Weight: 948 KB
• Volume: 11
• Category: Article
• ISSN: 0013-7944
• DOI: 10.1016/0013-7944(79)90137-1

✦ Synopsis

Almract--The plastic work required for a unit area of fatigue crack propagation U was measured by cementing tiny foil strain gages ahead of propagating fati~le cracks and recording the stress-strain curves as the crack approached. Measurements of U and plastic zone size in aluminum alloys 2024-T4, 2219-T861, 2219 oversged, and AI-6.3 wt~ Cu--T4, and a binary Hi-base alloy with 7.2wt% AI are herein reported. The results are discussed along with previously reported measurements of U in three steels and 7050 aluminum alloy. When U is compared to the fatigue crack propngation rate at constant h~ along with strength and modulus, the conclusion is drawn that U is one of the parameters which determines the rate of fatigue crack propagation. The relation of U to microstructure is also discussed. "Homolgeneous" plastic deformation in the plastic zone ahead of the crack seems desirable.