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利用ＳＥＭ和ＴＥＭ研究了Ｔｉ３Ａｌ基合金室温和６５０℃下恒应力低周疲劳的断口形貌和变形行为。研究表明，疲劳裂纹均起源于试样表面缺口处，室温下断口呈解理特征；６５０℃下断口中可观察到延性疲劳条带，且有沿晶的二次裂纹。合金的变形集中于β转变组织，β转变组织主要通过位错运动及形变孪晶的产生来协调变形，初生α２相晶内亚晶协调变形，６５０℃时非基面弯曲位错的开动使塑性变形更加有利。
The fracture surface morphology and deformation behavior of Ti3Al-based alloys under constant stress and low cycle fatigue at room temperature and 650 ℃ were studied by SEM and TEM. The results show that all the fatigue cracks originate from the notch at the specimen surface and show cleavage at room temperature. The ductile fatigue zone can be observed in the fracture at 650 ℃, and there are secondary cracks along the grain boundary. The deformation of the alloy concentrates on the β-transformation structure. The β-transformation structure coordinates the deformation mainly through the dislocation movement and the deformation twins. The deformation of the sub-crystals in the primary α2 phase is coordinated. The onset of non-basal bending dislocation at 650 ℃ Deformation more favorable.