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采用二次电子线扫描法研究了锆－４合金ＲＴ、４００℃和６００℃下疲劳断口分形特征，指出锆－４合金疲劳断口是一种与晶粒尺寸相当的材料组织层次上的分形结构；随着断口分形维数的增大，相应的疲劳寿命单调递增。认为相同循环塑性应变幅下，随着试验温度升高，疲劳过程中蠕变作用加强，断口表面蠕变空洞和二次裂纹数量明显增加，断口表面粗糙度增加是疲劳断口分形维数增大的原因。
The fracture characteristics of zirconium-4 alloy at RT, 400 ℃ and 600 ℃ were studied by means of secondary electron scanning. It was found that the fracture surface of zirconium-4 alloy was a fractal structure at the microstructure level corresponding to the grain size. As fracture fractal dimension increases, the corresponding fatigue life increases monotonically. It is considered that under the same cyclic plastic strain amplitude, as the test temperature increases, the creep effect during fatigue increases, the number of creep voids and secondary cracks on the fracture surface increases obviously, and the increase of fracture surface fracture surface fractal dimension increases with the increase of fracture surface roughness the reason.