Solution-treated 7075 Al alloy is subjected to equal-channel angular pressing (ECAP) and subsequent aging treatment. Fatigue crack growth (FCG) behavior of the samples in three different states was then evaluated, namely as-received, post-ECAP naturally aged and post-ECAP artificially aged. Compared to the as-received one, it is found that ECAP and subsequent natural aging have led to a considerable increase in fatigue crack growth rate. Furthermore, FCG resistance is greater in the artificially aged specimen compared to the naturally aged one. ΔK_c of the artificially aged specimen is larger than that of the naturally aged one, but smaller than that of the as-received specimen which represents higher fracture toughness.

固溶处理的 7075 铝合金经过等通道角挤压 (ECAP) 和随后的时效处理。然后评估样品在三种不同状态下的疲劳裂纹扩展 (FCG) 行为，即原样、ECAP 后自然时效和 ECAP 后人工时效。与原样相比，发现 ECAP 和随后的自然时效导致疲劳裂纹扩展速率显着增加。此外，与自然老化样品相比，人工老化样品的 FCG 抗性更大。人工时效试样的Δ K _c大于自然时效试样的Δ K _c，但小于原始试样的Δ K _c，代表更高的断裂韧性。