ラフト構造を有する一方向凝固Ni基超合金の疲労き裂進展と異方性

抄録

The effect of morphological change in microstructure called by ‘rafting’ on fatigue crack growth (FCG) behavior of a directionally solidified Ni-base superally has been investigated. The FCG tests have been conducted in the rafted and non-rafted CT specimens. The anisotropic characteristics in the FCG rate were also explored. The crack growth rate of the rafted specimens was lower than that of non-rafted specimens at room temperature. At 600°C, the difference in crack growth behavior got significant. These results were discussed in relation to the crack propagation mode.