Effects of laser peening on the fatigue strength and defect tolerance of aluminum alloy
Effects of laser peening on the fatigue strength and defect tolerance of aluminum alloy
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DOI：
10.1111/ffe.13201
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发表时间：
2020-01-24
影响因子：
3.7
通讯作者：
Kumeno, Fumiaki
中科院分区：
文献类型：
--
作者：
Takahashi, Koji;Kogishi, Yuta;Kumeno, Fumiaki
研究了激光强化对7075-T651铝合金弯曲疲劳强度的影响。在此基础上，从断裂力学的角度对铝合金的缺陷容限进行了探讨。结果表明，与喷丸强化（SP）相比，LP强化产生了更大的残余压应力。两种喷丸方式均能提高材料的疲劳强度。在LP和SP的应用基础上，深度小于0.4 mm和0.1 mm的半圆形裂缝分别变得无害。表观阈值应力强度因子范围δ K-th和K-ap分别增加了约5倍和2倍。δ K-th、K-ap的增大是由喷丸引起的残余压应力引起的。激光喷丸试样的Kitagawa-Takahashi图表明，LP提高了铝合金的缺陷容限。
The effects of laser peening (LP) on the bending fatigue strength of the 7075-T651 aluminum alloy were investigated. Accordingly, the defect tolerance of the aluminum alloy subjected to LP is discussed on the basis of fracture mechanics. The results indicate that a deeper compressive residual stress was induced by LP compared with the case of shot peening (SP). The fatigue strengths increased when both peening types were used. Semicircular slits with depths less than 0.4 and 0.1 mm were rendered harmless on the basis of the applications of LP and SP, respectively. The apparent threshold stress intensity factor range Delta K-th,K-ap increased by approximately five and two times owing to LP and SP, respectively. The increase of the Delta K-th,K-ap was caused by the compressive residual stress induced by the peening. The Kitagawa-Takahashi diagram of the laser-peened specimens shows that the defect tolerance of the aluminum alloy was improved by LP.