El-Khoury Mikhael, Voisiat Bogdan, Kunze Tim, Lasagni Andrés Fabián
Institut für Fertigungstechnik, Technische Universität Dresden, George-Bähr-Str. 3c, 01069 Dresden, Germany.
Fraunhofer-Institut für Werkstoff- und Strahltechnik IWS, Winterbergstr. 28, 01277 Dresden, Germany.
Materials (Basel). 2020 Sep 15;13(18):4101. doi: 10.3390/ma13184101.
In this study, we report on the optimization of the direct laser interference patterning process by applying the design of experiments approach. The periodic line-like microstructures of a 8.50 µm spatial period were fabricated by a two-beam interference setup with nanosecond laser pulses, varying laser fluence, pulse overlap, and hatch distance. Central composite design with three factors and five levels was implemented to optimize the required number of experiments. The experimental and numerical results show the impact of various structuring process parameters on surface uniformity. The responses measured are the structure height, height error, and waviness of the pattern. An analysis of the microstructures on the patterned surface was conducted by confocal microscopy and scanning electron microscopy. A 3D-characterization method based on morphological filtering, which allows a holistic view of the surface properties, was applied, and a new qualification scheme for surface microstructures was introduced. Empirical models were also developed and validated for establishing relationships between process parameters and performance criteria. Multi-objective optimization was performed to achieve a minimal value of structure height errors and waviness.
在本研究中，我们报告了通过应用实验设计方法对直接激光干涉图案化工艺进行优化的情况。利用纳秒激光脉冲的双光束干涉装置，通过改变激光能量密度、脉冲重叠率和扫描间距，制备了空间周期为8.50 µm的周期性线状微结构。采用三因素五水平的中心复合设计来优化所需的实验次数。实验和数值结果表明了各种结构化工艺参数对表面均匀性的影响。所测量的响应包括结构高度、高度误差和图案的波纹度。通过共聚焦显微镜和扫描电子显微镜对图案化表面的微结构进行了分析。应用了一种基于形态学滤波的三维表征方法，该方法能够全面观察表面特性，并引入了一种新的表面微结构鉴定方案。还开发并验证了经验模型，以建立工艺参数与性能标准之间的关系。进行了多目标优化，以实现结构高度误差和波纹度的最小值。
