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利用ＴＥＭ原位应变观察技术研究了ＴｉＡｌ合金ＰＳＴ晶体中裂纹扩展过程。发现界面与裂纹的交互作用与界面类型有关，不对称的伪孪晶界面（γ／γＰ）对裂纹扩展的阻碍最强烈。片层界面以及二次裂纹导致的裂纹分叉是层状组织韧化ＴｉＡｌ合金的重要原因。当裂纹与片层界面的夹角不同时，γ相所表现的两种截然不同的断裂方式表明在ＴｉＡｌ合金的脆性本质中包含有位错动力学的因素。
The crack propagation in TiAl alloy PST crystal was investigated by TEM in situ strain observation. It is found that the interaction between the interface and the crack is related to the type of interface, and asymmetric pseudo twin interface (γ / γP) has the strongest resistance to crack propagation. The interface of the lamellar and the crack bifurcation caused by the secondary cracks are the important reasons for the TiAl alloy layer toughening. When the angle between crack and lamellar interface is different, the two distinct modes of fracture exhibited by γ phase indicate that the dislocation kinetics are included in the brittleness of TiAl alloy.