Abstract
It is well-established that the fatigue crack growth behavior of aerospace aluminum alloys in high altitude applications is sensitive to both temperature and water vapor pressure. To isolate the role of temperature, fatigue crack growth experiments were performed on AA7075-T651 under ultra-high vacuum conditions (<6x10−6 Pa) at temperatures ranging from 23 °C to −65 °C. All da/dN–ΔK relationships exhibit the following: (1) a temperature-independent Paris regime at high ΔK, (2) a transition from the Paris regime to a sharply reduced da/dN, which occurs at higher ΔK as the temperature decreases, and (3) a coalescence in da/dN for all temperatures in the threshold region. Interestingly, the point of deviation from the Paris regime is found to correlate with a transition from a flat, transgranular fracture morphology to slip band cracking (SBC) across all conditions. The likely mechanisms governing the observed behaviors are discussed, focusing on the role of slip.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
