Cheng Yang, Lu Yu, Yang Qing, Zhong Jun, Xu Mengchen, Gou Xiaodan, Kai Lin, Hou Xun, Chen Feng
School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an 710049, China.
State Key Laboratory for Manufacturing System Engineering, Shaanxi Key Laboratory of Photonics Technology for Information, School of Electronic Science and Engineering, Xi'an Jiaotong University, Xi'an 710049, China.
Nanomaterials (Basel). 2022 Dec 8;12(24):4378. doi: 10.3390/nano12244378.
The preparation of the wavelength-scale micropores on metallic surfaces is limited by the high opacity of metal. At present, most micropores reported in the literature are more than 20 µm in diameter, which is not only large in size, but renders them inefficient for processing so that it is difficult to meet the needs of some special fields, such as aerospace, biotechnology, and so on. In this paper, the rapid laser fabrications of the wavelength-scale micropores on various metallic surfaces are achieved through femtosecond MHz burst Bessel beam ablation. Taking advantage of the long-depth focal field of the Bessel beam, high-density micropores with a diameter of 1.3 µm and a depth of 10.5 µm are prepared on metal by MHz burst accumulation; in addition, the rapid fabrication of 2000 micropores can be achieved in 1 s. The guidelines and experimental results illustrate that the formations of the wavelength-scale porous structures are the result of the co-action of the laser-induced periodic surface structure (LIPSS) effect and Bessel beam interference. Porous metal can be used to store lubricant and form a lubricating layer on the metallic surface, thus endowing the metal resistance to various liquids' adhesion. The microporous formation process on metal provides a new physical insight for the rapid preparation of wavelength-scale metallic micropores, and promotes the application of porous metal in the fields of catalysis, gas adsorption, structural templates, and bio-transportation fields.
金属表面波长尺度微孔的制备受到金属高不透明度的限制。目前，文献报道的大多数微孔直径超过20 µm，不仅尺寸大，而且加工效率低，难以满足航空航天、生物技术等一些特殊领域的需求。本文通过飞秒兆赫兹脉冲贝塞尔光束烧蚀实现了在各种金属表面快速制备波长尺度的微孔。利用贝塞尔光束的长景深焦场，通过兆赫兹脉冲积累在金属上制备了直径为1.3 µm、深度为10.5 µm的高密度微孔；此外，1 s内可实现2000个微孔的快速制备。指导原则和实验结果表明，波长尺度多孔结构的形成是激光诱导周期性表面结构（LIPSS）效应和贝塞尔光束干涉共同作用的结果。多孔金属可用于储存润滑剂并在金属表面形成润滑层，从而赋予金属抵抗各种液体粘附的能力。金属上微孔的形成过程为快速制备波长尺度的金属微孔提供了新的物理见解，并推动了多孔金属在催化、气体吸附、结构模板和生物传输等领域的应用。
