Evaluation of selective laser sintering processes by optical coherence tomography
Evaluation of selective laser sintering processes by optical coherence tomography
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DOI：
10.1016/j.matdes.2015.09.084
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发表时间：
2015-12-25
影响因子：
8.4
通讯作者：
Clare, Adam T.
中科院分区：
文献类型：
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作者：
Guan, Guangying;Hirsch, Matthias;Clare, Adam T.
选择性激光烧结 (SLS) 可以直接根据 3D CAD 数据快速、灵活且经济高效地生产零件。与更成熟的机床不同，它明显缺乏关键过程变量的过程监控和反馈控制。现场分析技术允许修复技术的出现、生产参数的过程优化，并且还可以节省时间和材料。在这项研究中，首次使用光学相干断层扫描 (OCT) 来评估 SLS 生产的组件。使用聚酰胺-PA2200 分析表面缺陷并量化与测量技术相关的限制因素。 OCT 被证明是一种有用的技术，可用于评估由于烧结不良或粉末铺展不均匀而导致的表面不规则性以及亚表面缺陷。我们展示了对表面缺陷（例如裂纹、孔隙和空隙）的检测和量化，尺寸类似于 30 μm。此外，我们还表明，该技术可以解析表面以下 200 至 400 pm 深度内的“内置”精细特征，覆盖该工艺使用的典型层厚度。此功能为实时监控 SLS 流程以确保安全，甚至在构建过程中动态纠正缺陷铺平了道路。 (C) 2015 年作者。由 Elsevier Ltd 出版。这是一篇基于 CC BY 许可证 (http://creativecommons.org/licenses/by/4.0/) 的开放获取文章。
Selective laser sintering (SLS) enables the fast, flexible and cost-efficient production of parts directly from 3D CAD data. Unlike more established machine tools, there is a marked lack of process monitoring and feedback control of key process variables. In-situ analysis techniques permit the emergence of repair techniques, in-process optimization of production parameters, and will also serve to save time and material. In this study, optical coherence tomography (OCT) is used for the first time to evaluate components produced by SLS. Using a Polyamide-PA2200, surface defects are analyzed and the limiting factors associated with the measurement technique are quantified. OCT is shown to be a useful technique for evaluating surface irregularities alongside sub-surface defects that have resulted from poor sintering or non-homogeneous powder spreading. We demonstrate detection and quantification of surface defects such as cracks, pores and voids on a similar to 30 mu m scale. Furthermore, we show that this technique can resolve 'built-in' fine features within a 200 to 400 pm depth below the surface, covering typical layer thicknesses used by this process. This capability paves the way for real-time monitoring of the SLS process for assurance, or even dynamic correction of defects during the build. (C) 2015 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).