Investigation on the influence of crystal orientation on the fatigue characteristics of thin-walled specimens with varying bending angles of nickel-based single-crystal alloys with film cooling hole

Abstract In this paper, nickel-based single crystal thin-walled specimens with different bending angles were designed. The effect of crystal orientation on the fatigue properties of thin-walled specimens with film cooling hole at 900 °C was investigated by using crystal plastic slip theory. The results show that the Mises stress around the film cooling hole under three crystal orientations [001], [011] and [111] is concentrated in the vertical loading direction, forming four banded stripes, and the order of maximum Mises stress is [111] > [011] > [001]. The change of crystal orientation leads to the difference of stress distribution and stress gradient, and the stress gradient increases with the increase of curvature. The distribution of maximum shear stress under different crystal orientations is different, and the change of bending degree does not affect its direction distribution. In addition, the activation of the octahedral slip system around the film cooling hole under different crystal orientations was analyzed. It was found that the number of octahedral slip systems activated by [001] and [011] orientations was the same, while the number of octahedral slip systems activated by [111] orientation was less.