Abstract
Department of Mechanical Engineering and Mechanics, Zettlemoyer Center forSurface Studies, Lehigh University, Bethlehem, PA 18015, USA(Received September 25, 2000)(Accepted in revised form January 11, 2001)Keywords: Oxygen enhanced crack growth; X-ray photoelectron spectroscopy (XPS); Niobium;Crack growth mechanism; Ni base alloyIntroductionNickel based superalloys are used extensively in high temperature applications, for example, turbinedisks in jet engines. Since turbine discs operate in air at 700 to 973 K, these alloys have receivedconsiderable attention with respect to their sensitivity to environmentally enhanced crack growth(EECG). Previous studies have shown that oxygen increased the rates of crack growth in niobiumcontaining alloys (such as Inconel 718, Rene-95 and3750) at high temperatures (.800K) by up to 4.5orders of magnitude over those observed in an inert environment (1–7). Several mechanisms have beensuggested for this crack growth enhancement which include: (a) the oxidation of metallic carbides orcarbon at the grain boundaries to form high pressures of CO and CO
Sign-in/Register to access full text options 
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.
