Jakob Severin, Pfeifenberger Manuel J, Hohenwarter Anton, Pippan Reinhard
Erich Schmid Institute of Materials Science, Austrian Academy of Sciences, Leoben, Austria.
Department of Physical Metallurgy and Materials Testing, Montanuniversitaet Leoben, Leoben, Austria.
Sci Technol Adv Mater. 2017 Aug 22;18(1):574-583. doi: 10.1080/14686996.2017.1360751. eCollection 2017.
The standard preparation technique for micro-sized samples is focused ion beam milling, most frequently using Ga ions. The main drawbacks are the required processing time and the possibility and risks of ion implantation. In contrast, ultrashort pulsed laser ablation can process any type of material with ideally negligible damage to the surrounding volume and provides 4 to 6 orders of magnitude higher ablation rates than the ion beam technique. In this work, a femtosecond laser was used to prepare wood samples from spruce for mechanical testing at the micrometre level. After optimization of the different laser parameters, tensile and compressive specimens were produced from microtomed radial-tangential and longitudinal-tangential sections. Additionally, laser-processed samples were exposed to an electron beam prior to testing to study possible beam damage. The specimens originating from these different preparation conditions were mechanically tested. Advantages and limitations of the femtosecond laser preparation technique and the deformation and fracture behaviour of the samples are discussed. The results prove that femtosecond laser processing is a fast and precise preparation technique, which enables the fabrication of pristine biological samples with dimensions at the microscale.
微尺寸样品的标准制备技术是聚焦离子束铣削，最常用的是镓离子。其主要缺点是所需的处理时间以及离子注入的可能性和风险。相比之下，超短脉冲激光烧蚀可以处理任何类型的材料，对周围体积的损伤理想情况下可忽略不计，并且提供比离子束技术高4到6个数量级的烧蚀速率。在这项工作中，使用飞秒激光从云杉制备木材样品，用于微米级的力学测试。在优化不同的激光参数后，从微切片的径切和弦切以及纵切和弦切截面制作拉伸和压缩试样。此外，在测试之前，将激光处理过的样品暴露于电子束下，以研究可能的束损伤。对源自这些不同制备条件的试样进行力学测试。讨论了飞秒激光制备技术的优点和局限性以及样品的变形和断裂行为。结果证明，飞秒激光加工是一种快速且精确的制备技术，能够制造尺寸在微观尺度的原始生物样品。
