通过对单晶［００１］取向的慢拉伸断裂行为研究发现，与真空中相比，空气中氧对单晶７６０℃温度下慢拉伸性能以及８５０℃温度下慢拉伸强度影响不大，但使８５０℃时单晶的延性下降；氧的存在不影响单晶的断裂方式，而改变单晶拉伸试样表面裂纹的扩展；空气中慢拉伸断口的主裂纹源位于断口边缘，而真空中主裂纹源则位于断口中间部位；无论是真空还是空气中，慢拉伸断裂为多源开裂，断口中存在（００１）方形结晶面包围的孔洞。 Through the slow tensile fracture behavior of single crystal [001] orientation, it was found that the oxygen in the air had little effect on the slow tensile properties of single crystal at 760 ℃ and the slow tensile strength at 850 ℃, However, the ductility of the single crystal decreases at 850 ℃. The presence of oxygen does not affect the fracture mode of the single crystal, but changes the surface crack propagation in the single crystal tensile specimen. The main crack source in the slow- The source of the main cracks in the vacuum is located in the middle part of the fracture. Whether in vacuum or air, the slow tensile fracture is multi-source cracking, and there are holes surrounded by the (001) square crystal face in the fracture.