Effect of porosity and eutectics on the high-temperature low-cycle fatigue performance of a nickel-base single-crystal superalloy

This study examines the impact of porosity and γ/γ′-eutectics on the low-cycle fatigue life of a single-crystal Ni-based superalloy at high temperatures. Various material variants were produced using different heat treatments, including hot isostatic pressing. Electron microscopy revealed that both pores and γ/γ′-eutectics initiate cracks, leading to early failure. The findings suggest that remaining γ/γ′-eutectics may weaken fatigue resistance more than pores. Additionally, proper integrated hot isostatic pressing heat treatments enhance fatigue performance.