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系统地研究了［１１０］与［１００］两种特殊晶轴取向的高纯铝单晶在１×１０（－４）－６×１０（－４）室温拉压疲劳应变振幅条件下的应力σｍ、内耗Ｑ（－１）和加载最大处超声衰减△αｔ，的循环响应行为，对疲劳不同阶段的位错组态作了详细的ＴＥＭ观察。结果表明：两种单晶的循环应力均显示出“硬化－软化－二次硬化”的三个阶段特征。内耗的变化和应力进程同步，但趋势相反．超声衰减开始随圈数增大，达到一极大值后减小。这三种参数的变化是由位错与位错的相互作用机制控制。
The stress σm of high purity pure aluminum single crystal with [110] and [100] orientations was systematically studied under 1 × 10 (-4) -6 × 10 (-4) room temperature tension and compression fatigue strain amplitude , The internal response Q (-1) and the ultrasonic attenuation △ αt at the maximum load, the dislocation configurations at different stages of fatigue were observed in detail. The results show that the cyclic stresses of the two kinds of single crystals all show the three stages of “hardening - softening - secondary hardening”. The change of internal friction and the stress process are synchronized, but the trend is opposite. Ultrasonic attenuation began to increase with the number of turns, reaching a maximum and then decrease. The changes of these three parameters are controlled by the interaction mechanism between dislocation and dislocation.