Laser peen forming induced two way bending of thin sheet metals and its mechanisms
Laser peen forming induced two way bending of thin sheet metals and its mechanisms
复制标题
激光喷丸成形诱导薄板双向弯曲及其机理
DOI：
10.1063/1.3486218
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发表时间：
2010-10-01
影响因子：
3.2
通讯作者：
Hu, Jun
中科院分区：
文献类型：
--
作者：
Hu, Yongxiang;Xu, Xiaoxia;Hu, Jun
激光喷丸成形是一种利用激光能量形成复杂形状或改变曲率的纯机械成形方法。它是灵活的，独立的工具不准确的磨损和偏转的结果。它的非热工艺使得在没有材料降解的情况下形成金属板成为可能，甚至通过在目标表面上诱导压应力来改善它们。通过实验研究了激光强度、扫描速度等工艺参数对不同厚度薄板弯曲变形的影响。研究发现，根据加工条件的不同，金属板不仅可以朝向激光束弯曲，而且可以远离激光束弯曲。通过增加板料厚度或降低激光强度，弯曲变形从凹状到凸状连续而平滑地变化。也有一个特定的厚度为金属板保持平坦后，激光喷丸成形。提出了两种机制来理解所有的实验结果，这是冲击弯曲机制和应力梯度机制弯曲朝向和远离激光束，分别。由于两种机构的耦合作用，可根据工艺条件从一种机构平稳切换到另一种机构，使激光喷丸成形成为一种易于控制的成形复杂形状和高精度曲率修正的工艺。
Laser peen forming, is a purely mechanical forming method achieved through the use of laser energy to form complex shapes or modify curvatures. It is flexible and independent of tool inaccuracies that result from wear and deflection. Its nonthermal process makes it possible to form sheet metal without material degradation or even improve them by inducing compressive stress over the target surface. Experimental investigation has been carried out to understand the effect of process parameters such as laser intensity, scanning velocity on the bendingdeformation of thin sheet metal with different thicknesses. It is found that the sheet metal can be made to bend not only toward but also away from the laser beam depending on the process condition. The bendingdeformation is found to be varied continuously and smoothly from the concave form to the convex by increasing the sheet thickness or decreasing the laser intensity. There is also a specific thickness for sheet metal to remain flat after laser peen forming. Two mechanisms are proposed to understand all experimental results, which are shock bending mechanism and stress gradient mechanism for bending toward and away from the laser beam, respectively. Due to the coupling effect of two mechanisms, the smoothly switching from one mechanism to the other depending on process conditions makes the laser peen forming to be an easily controlled process for forming complex shapes and high precision curvature modification.