Effect of Temperature and Strain Amplitude on Low Cycle Fatigue Behaviour of DD11
The fatigue behaviours, including the fatigue cycle life, cyclic stress response, microstructure evolution and the fatigue fracture morphology of DD11 alloy with [0 0 1] orientation under the isothermal low cycle fatigue condition at 760 and 980 °C were investigated. The fatigue life decreased significantly with increasing total strain amplitude, but did not decrease with increasing temperature. The cyclic softening was related to the climb and cross-slip of dislocations. The dislocations which cut through the γ′ phase caused cyclic hardening. The fracture mode included shear fracture and normal fracture. This work is beneficial to build the relationship between microstructure and cyclic stress response behaviour.
KeywordsLow cycle behaviour Cyclic softening and hardening behaviour Fatigue life Dislocation
This study was financially supported by Beijing Natural Science Foundation (2184132).
- 1.R.C. Reed, Superalloys: Fundamentals and Applications (Cambridge University Press, 2006)Google Scholar
- 2.M. McLean, Directionally Solidified Materials for High Temperature Service (The Metals Society, London, 1983)Google Scholar
- 3.K.H. David E. Laughlin, Physical Meallurgy, vol. III, 5th edn. (Elsevier, USA, 2014)Google Scholar
- 11.N.T.R. Ohtani, M. Shibata, S. Taniyama, High temperature fatigue of the nickel-base single-crystal superalloy CMSX-10. Fatigue Fract. Eng. Mater. Struct. 867–876 (2001)Google Scholar