用正电子湮没寿命方法和超声衰减方法对金属铝合金和钢疲劳样品进行了测量。结果表明，在疲劳加载次数较小时，正电子参数将随着疲劳加载次数的增加而增加；但当疲劳加载次数足够大时，金属样品内部发生了结构的变化，如空位之间发生合并而形成空位团，位错之间发生合并、缠绕，这些结构的变化导致正电子平均寿命在到达最大值后下降。在用超声方法对金属疲劳样品进行测量时，观察到衰减常数有类似的变化趋势。 The fatigue life of metal aluminum alloy and steel samples were measured by positron annihilation lifetime method and ultrasonic attenuation method. The results show that the positron parameters increase with the increase of the fatigue loading times when the fatigue loading times are small. However, when the fatigue loading times are large enough, structural changes occur in the metal samples, such as the merger of vacancies Gaps and dislocations merge and twist, and the changes of these structures lead to the decrease of the average positron lifetime after reaching the maximum value. A similar trend of decay constants was observed when the metal fatigue samples were measured by ultrasound.