摘要
The influence of the grain boundary on the fatigue behavior of Ni-base bicrystals was studied by two three-point-bending (TPB) specimens. One TPB specimen was named Bicrystal 1, whose pre-crack was along the grain boundary and the applied load paralleled to the pre-crack direction, while the other TPB specimen was named Bicrystal 2, whose pre-crack was perpendicular to the grain boundary and the applied load paralleled also to the pre-crack direction. It was found that the fatigue crack growth rate of Bicrystal 1 was about a tenfold higher than that of Bicrystal 2. The fatigue behavior of Bicrystal 2 specimen was dependent on the distance between the crack tip and the grain boundary. The crack growth rate was the highest when the crack tip was at a critical distance to the grain boundary, while the crack growth rate was the lowest when the crack tip reached the grain boundary. After the crack was over the grain boundary, the crack growth rate increased. The crystallographic finite element method was applied to analyze the stress and the strain structure ahead of the crack in order to reveal the above characteristics of the fatigue behavior. It is the grain boundary-induced redistribution of stresses near the crack tip that induces the difference of fatigue behavior.
| 源语言 | 英语 |
|---|---|
| 页（从-至） | 69-72 |
| 页数 | 4 |
| 期刊 | Journal of Materials Science and Technology |
| 卷 | 18 |
| 期 | 1 |
| 出版状态 | 已出版 - 1月 2002 |