通过单轴压缩及TEM原位拉伸研究了全层状TiAl合 金(PST晶体)中α2板条的形变和断裂特 征。结果表明， 全层状TiAl合金中α2相形变和断裂特征与加载方向有关。当片层与 加载轴平行时 ， α2相中的滑移沿柱面进行， 微裂纹优先在α2相内(沿柱面)形核； 而 当片层与加载轴垂 直时， 形变困难， α2相中的滑移将沿角锥面进行， 微裂纹很容易沿相界面形 核、 扩展。
The deformation and fracture characteristics of α2 plates in fully la mellar TiAl alloys (PST crystals) were investigated through uniaxial compression and in-situ TEM technique. The results indicate that the deformation and frac ture characteristics of α2 plates in fully lamellar TiAl alloys are rel ated to the loading direction. When the lamellae are parallel to the loading axis， t he slips in α2 plates occur along prism planes and microcracks form pr efe rentially within α2 plates (along prism planes); when the lamellae are perpend icular to the loading axis， the deformation is relatively difficult， and the slips in α2 plates occur along pyramidal planes and microcracks form ea sily and propagate along γ/α2 interfaces.
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