2524-T3铝合金铆钉填充锪窝孔疲劳特性研究

2524-T3铝合金被认为是目前综合性能最好的飞机蒙皮用铝合金,研究其在疲劳载荷状态下的力学性能对材料的安全使用具有重要的意义。通过疲劳试验研究2524-T3铝合金铆钉填充锪窝孔试样在一种典型应力比、不同载荷水平下的疲劳性能,得到铆钉填充锪窝孔试样疲劳裂纹寿命的p-S-N曲线,同时借助扫描电镜观察疲劳裂纹的萌生和扩展行为。研究结果表明：2524-T3铝合金铆钉填充锪窝孔试样具有良好的抗疲劳损伤性能;在指定疲劳寿命条件为3×106周次下,试样在室温轴向疲劳加载条件下的条件疲劳极限为108MPa;疲劳断口由疲劳源区、裂纹扩展区及瞬断区组成。

Study on Fatigue Performance of 2524-T3 Aluminum Alloy with Rivet-filled Countersink Hole

2524-T3 aluminum alloy is considered as the best aluminum alloy for the aircraft skin which have the excellent comprehensive performance. Mechanical performance research of this material is of important significance for safely using of material. The fatigue performance of 2524-T3 aluminum alloy with rivet-filled countersink holes is investigated under a certain type stress ratio and different stress level. Probability S-N curves of fa- tigue life are calculated. The fatigue crack initiation and propagation behavior are observed by scanning electron microscopy. The results indicate that 2524-T3 alloy has superior fatigue properties. The fatigue strength of specimens with rivet-filled countersink holes is 108 MPa in room temperature axial fatigue load, when the fatigue life is 3 X 106 cycles. The fatigue fracture surface consists of fatigue crack source, fatigue crack growth area and instantaneous fracture area.