Geometry dependent microstructures: bug or feature?
Geometry dependent microstructures: bug or feature?
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几何相关的微观结构：缺陷还是功能？
DOI：
10.1016/j.procir.2018.08.024
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发表时间：
2018
期刊：
影响因子：
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通讯作者：
M. Schmidt
中科院分区：
文献类型：
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作者：
J. Hagen;M. Rasch;S. Kohl;M. Schmidt
选择性激光熔化（SLM）不仅保证几何自由，而且设想允许定制的微观结构。虽然能够在零件的某些区域构建选定的微观结构的可能性通常被视为一种特征，但由于几何形状的变化而导致的微观结构的局部变化通常被视为缺陷。由于微观组织的形成取决于局部温度梯度和凝固速率，因此模拟必须能够预测这两个量以反映实验结果。通过零件尺度的热力学模拟和粉末尺度的热流体模拟，揭示了几何形状对温度梯度和凝固速率的影响。能够预测这些数量，用户可以主动决定特征和缺陷，并相应地调整工艺参数。
Selective laser melting (SLM) promises not only geometric freedom, but is envisioned to allow tailored microstructures as well. While the possibility to be able to build chosen microstructures in certain areas of a part is often seen as a feature, the local change in microstructure due to a changing geometry is just as often seen as a bug. Since the formation of microstructure depends on local temperature gradient and solidification rate, simulations must be able to predict both quantities to reflect experimental results. We use thermomechanical simulations on the part scale and thermofluidic simulations on the powder scale to show the influence of geometry on the temperature gradient and solidification rate. Being able to predict these quantities the user can actively decide between feature and bug and adjust process parameters accordingly.