采用根据国内某型飞机飞行特性编制的随机载荷谱，对B95和7B04硬质铝合金进行疲劳试验，获得疲劳裂纹扩展数据和疲劳总寿命，确定裂纹形成寿命，对2种铝合金的疲劳寿命、分散性系数等重要疲劳性能指标进行对比分析。结果表明：7B04铝合金的中值裂纹形成寿命为5 301.9飞行小时，约为B95铝合金的1.55倍，裂纹形成寿命分散系数为1.436 2，远低于B95铝合金的（2.443 9）；7B04铝合金的安全寿命为4 373.82飞行小时，约为B95铝合金的2.2倍，总寿命分散系数为1.502 3，亦远低于B95铝合金的（2.168 9）；7B04铝合金的疲劳裂纹扩展性能明显优于B95铝合金的，可替代B95铝合金制造结构件。

Fatigue tests were carried out on B95 and 7B04 superhard aluminum alloys under the random load spectrum compiled by the flight characteristics of a domestic aircraft, and the fatigue crack growth data and total fatigue life were obtained. The crack formation life was determined, and the fatigue life, dispersion coefficient and other important fatigue property indexes of the two aluminum alloys were compared and analyzed. The results show that the median crack formation life of 7B04 aluminum alloy was 5 301.9 flight hours, which was about 1.55 times that of B95 aluminum alloy, and the dispersion coefficient of crack formation life was 1.436 2, which was far lower than that of B95 aluminum alloy (2.443 9). The safe life of 7B04 aluminum alloy was 4 373.82 flight hours, which was about 2.2 times that of B95 aluminum alloy, and the total life dispersion coefficient was 1.502 3, which was far lower than that of B95 aluminum alloy (2.168 9). The fatigue crack growth properties of 7B04 aluminum alloy were obviously better than those of B95 aluminum alloy, so it could be used to replace B95 aluminum alloy to manufacture structural members.