ON THE LOW-CYCLE FATIGUE FRACTURE BEHAVIOR OF A SINGLE CRYSTAL NICKEL-BASED SUPERALLOY WITH SURFACE RECRYSTALLIZED GRAINS

摘要

The low-cycle fatigue fracture behaviors of a single crystal nickel-based superalloy with partially recrystallized grains were investigated at elevated temperature. The recrystallized grains were found to decrease the fatigue life evidently with increasing thickness. The surface recrystallized superalloy was found to show temperature-dependent fracture behavior. At lower temperature, the crystallographic cracking feature of recrystallized grains was identified by EBSD measurements and analyzed by mechanistic methods.