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对层状结构TiAl在扫描电镜中原位拉伸，发现裂纹前端首先出现滑移带，只有当局部塑性变形发展到临界状态，位错塞积应力等于原子键合力时才会使微米尺寸的微裂纹不连续形核，裂纹可沿滑移带（滑移面是解理面之一）形核，也可沿其它解理面形核．随裂纹扩展，新的不连续裂纹形校的阻力（外加KI）不断增大。
The TiAl in the layered structure was stretched in-situ by scanning electron microscopy. It was found that the slip band appeared first in the crack tip. Only when the local plastic deformation developed to a critical state, the dislocation plugging stress equals the atomic bonding force, micro- Discontinuous nucleation, the crack along the slip band (slip surface is one of the cleavage plane) nucleation, but also along other cleavage plane nucleation. With the crack propagation, the resistance of the new discontinuous crack-shaped (plus KI) increases.