Life assessment of anisotropic low cycle fatigue of nickel-base single crystal superalloy

Anisotropic low cycle fatigue (LCF) behavior of nickel-base single crystal superalloy was studied in three distinct crystal orientations. Fractography analysis revealed that activated slip systems under tension were octahedral for the [001]/[011] specimens and cubic slip systems for the [111] specimens, respectively. Based on the critical slip plane concept, the resolved shear stress/strain and the normal stress/strain on slip planes were calculated, forming a damage factor for multiaxial fatigue. The virtual resolved strain energy model was proposed to describe the anisotropic fatigue behavior and extensively evaluated on different crystal orientations, strain ratios and temperatures. The predicted fatigue lives matched well with the experimental results.

Automated summary

In this study, the anisotropic low cycle fatigue behavior of nickel-base single crystal superalloy was investigated in different crystal orientations. Fractography analysis revealed the activated slip systems under tension and a virtual resolved strain energy model was proposed to describe the anisotropic fatigue behavior.