超声滚压强化对2D12铝合金疲劳性能的影响

Influence of Ultrasonic Surface Rolling on Fatigue Behavior of 2D12 Aluminum Alloy

摘要:

通过对比分析2D12铝合金超声强化试样与抛光试样的疲劳性能，对表面硬化、残余应力和疲劳寿命进行了研究。残余压应力和梯度纳米晶结构对改善构件的疲劳性能起着至关重要的作用，可以有效减少疲劳裂纹的萌生和扩展。实验及分析预测结果表明，试样经超声强化后，轴向压应力提高了55%，显微硬度提高了20%。通过对表面强化规律的研究，为2D12铝合金的强化工艺和疲劳性能的影响提供了指导。

Abstract:

The effects of ultrasonic rolling strengthening treatment and polishing on 2D12 aluminum alloys were investigated, and the surface hardening, residual stress, and fatigue life were studied. The residual compressive stress and gradient nano-crystalline structure can reduce the fatigue crack initiation and propagation, which play a critical role in improving fatigue performance of components. The results and analytic predictions indicate that after ultrasonic rolling strengthening treatment, the axial compressive stress and the microhardness of specimens are improved by 55% and 20%, respectively. The strengthening rule provides a guidance for strengthening process and the fatigue behavior improvement of 2D12 alloy.