Laser Cavitation Peening and Its Application for Improving the Fatigue Strength of Welded Parts
Laser Cavitation Peening and Its Application for Improving the Fatigue Strength of Welded Parts
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DOI：
10.3390/met11040531
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发表时间：
2021-04-01
期刊：
影响因子：
2.9
通讯作者：
Soyama, Hitoshi
中科院分区：
文献类型：
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作者：
Soyama, Hitoshi
在传统的浸没式激光喷丸过程中，激光烧蚀产生的冲击力被用来产生局部塑性变形凹坑，以提高金属材料的性能，例如疲劳性能。然而，在激光烧蚀之后产生表现为类似空化的气泡，称为“激光空化”。“相反，在传统的空化喷丸中，通过将高速水射流注入水中产生空化，并利用空化崩溃的影响进行机械表面处理。本文介绍了一种激光空化冲击机械表面处理机理，研究了激光空蚀强化对疲劳强度的改善作用。采用聚偏氟乙烯（PVDF）传感器和浸没式冲击波传感器测量了激光烧蚀和激光空泡溃灭引起的冲击力，并通过摄像机拍摄的高速视频测量了激光空泡的直径。结果表明，激光空泡溃灭的影响大于激光烧蚀的影响，且喷丸效果与激光空泡体积密切相关。激光空蚀强化提高了不锈钢焊缝的疲劳强度。
During conventional submerged laser peening, the impact force induced by laser ablation is used to produce local plastic deformation pits to enhance metallic material properties, such as fatigue performance. However, a bubble, which behaves like a cavitation, is generated after laser ablation, known as "laser cavitation." On the contrary, in conventional cavitation peening, cavitation is generated by injecting a high-speed water jet into the water, and the impacts of cavitation collapses are utilized for mechanical surface treatment. In the present paper, a mechanical surface treatment mechanism using laser cavitation impact, i.e., "laser cavitation peening", was investigated, and an improvement in fatigue strength from laser cavitation peening was demonstrated. The impact forces induced by laser ablation and laser cavitation collapse were evaluated with a polyvinylidene fluoride (PVDF) sensor and a submerged shockwave sensor, and the diameter of the laser cavitation was measured by observing a high-speed video taken with a camera. It was revealed that the impact of laser cavitation collapse was larger than that of laser ablation, and the peening effect was closely related to the volume of laser cavitation. Laser cavitation peening improved the fatigue strength of stainless-steel welds.