Abstract
Materials containing columnar grains might cause fatigue life reduction. In this study, fatigue tests were carried out for nickel-based superalloy polycrystals, which were composed of (i) columnar grains + equiaxed grains and (ii) only equiaxed grains. Polycrystalline FE analyses were conducted to estimate their fatigue lives. Resolved shear stresses ware calculated in expected twelve slip systems by FE analysis. Fatigue life was estimated based on the resolved shear stresses on primary slip plane. It was suggested that there were fatigue life reduction in materials containing columnar grains by FE analysis, but there was no significant difference between the two materials by fatigue tests.
