Affiliation:
1. NASA Lewis Research Center, Cleveland, OH 44135
2. Case Western Reserve University, Cleveland, OH 44135
Abstract
A study was done to determine the fatigue crack growth behavior of a PWA 1484 single-crystal nickel-base superalloy in a temperature range of 427°C to 871°C. Two distinctive failure modes were observed, which were a function of both temperature and frequency. At lower temperatures and higher frequencies crack growth occurred on the {111} octahedral slip planes at an oblique angle to the loading direction. Higher temperatures and decrease in frequencies favored angle to the loading direction. Higher temperatures and decrease in frequencies favored a Mode I type failure process. The failure mode transitions were explained by invoking arguments based on environmental damage mechanisms. The fatigue crack growth rate data were analyzed using three different crack driving force parameters. The parameters investigated consisted of the Mode I stress intensity parameter corrected for the inclined crack trajectory, and two different octahedral Mode II parameters, which are based on the calculation of resolved shear stresses on the {111} slip systems. The Mode I ΔK parameter did a fair job in correlating the data but did not collapse it into a single narrow band. The two octahedral crack driving force parameters, ΔKRSS and a newly proposed ΔKOCT, collapsed all the data into a single narrow band. In addition to correlating the fatigue crack growth rates, the two octahedral parameters also predicted the {111} planes on which the crack growth took place.
Subject
Mechanical Engineering,Energy Engineering and Power Technology,Aerospace Engineering,Fuel Technology,Nuclear Energy and Engineering
Reference11 articles.
1. Antolovich, S. D., and Jayaraman, N., 1983, “The Effect of Microstructure on the Fatigue Behavior of Ni Base Alloys,” in: Proc. of the 27th Sagamore Army Materials Research Conference, J. J. Burke and V. Weiss, eds., pp. 119–144.
2. Chan
K. S.
, and CruseT. A., 1986, “Stress Intensity Solutions for Anisotropic Compact Tension Specimen With Inclined Cracks,” Eng. Fracture Mechanics, Vol. 23, No. 5, pp. 863–874.
3. Chen, O. Y., 1985, “Crystallographic Fatigue Crack Propagation in Single Crystal Superalloys,” PhD Thesis, University of Connecticut, Storrs, CT.
4. Chen, Q., and Liu, H. W., 1988, “Resolved Shear Stress Intensity Coefficient and Fatigue Crack Growth in Large Crystals,” NASA CR-182137.
5. Cunningham, S. E., DeLuca, D. P., and Haake, F. K., 1994, Crack Growth and Life Prediction in Single Crystal Nickel Superalloys, Vol. 1, WL-TR-94-4089, Aug.
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