???????????TiAl??????????????о?

 本文通过拉伸试验研究了铸造TiAl合金单一取向层片组织在缺口应力集中系数分别为2、3和4时的缺口敏感性。发现，该合金在沿层片界面方向的应力作用下，对应各Kt水平的缺口试样均具有大于光滑试样的抗拉强度，且其缺口敏感系数相当；并根据该合金具有较好的拉伸塑性和缺口拉伸断口上存在裂纹萌生和稳态扩展区域的特征，分析讨论了其形成缺口强化效应的机制。

Notch Sensitivity of Lamellar TiAl Alloys With Monolithic Orientation

Notch sensitivity of TiAl alloys containing lamellar microstructure with monolithic orientation was investigated by notch tensile tests at 2,3 and 4 Kt levels.The tensile test results show that all notched specimens exhibited higher ultimate tensile strength than that of un-notched specimens under a load parallel to lamellar interfaces.The sensitivity coefficients calculated from the strength averages are approximate with respect to different Kt levels.Thereafter,the notch strengthening mechanisms are discu...