研究了７０７５Ｔ７３５１０合金的断裂韧性和疲劳裂纹扩展行为，分析了不同方向性能差异的原因结果表明：合金的断裂韧性依赖于取向，Ｌ—Ｔ方向的断裂韧性值远大于Ｔ—Ｌ方向，而其疲劳裂纹扩展速率对应力比更敏感，无论Ｔ—Ｌ还是Ｌ—Ｔ方向，Ｒ＝０．６时的ＦＣＧＲ值是Ｒ＝０．１时的二倍左右．在相同应力比和较小的△Ｋ下，两个方向的ＦＣＧＲ值基本无差异文中认为：呈带状分布或串状分布的杂质相对Ｔ—Ｌ向断裂韧性影响较大 The fracture toughness and fatigue crack propagation of 7075T73510 alloy were investigated. The reason of the difference in the performance of different directions was analyzed. The results show that the fracture toughness of the alloy depends on the orientation and the fracture toughness in the L-T direction is much larger than the T-L direction, The crack propagation rate is more sensitive to the stress ratio, regardless of the T-L or L-T direction, and the FCGR value at R = 0.6 is about twice as large as R = 0.1. In the same stress ratio and smaller △ K, the two directions of the FCGR value is basically no difference between the text that the ribbon distribution or string-like distribution of impurities relative to the T-L fracture toughness