Digital sand core physics: Predicting physical properties of sand cores by simulations on digital microstructures
Digital sand core physics: Predicting physical properties of sand cores by simulations on digital microstructures
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DOI：
10.1016/j.ijsolstr.2019.09.014
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发表时间：
2020-04-01
影响因子：
3.6
通讯作者：
Guenther, Daniel
中科院分区：
文献类型：
--
作者：
Ettemeyer, Florian;Lechner, Philipp;Guenther, Daniel
在这项工作中，我们将吹塑无机结合砂芯的强度、渗透率和导热系数的测量结果与数字生成的单胞模型在微米尺度上解析细砂粒-粘结剂集合体的模拟结果进行了比较。铸造应用中使用的砂芯的质量和可操作性受到所用砂和粘结剂的不同特性的强烈影响，如化学成分、孔隙率、粒度分布和粘结剂体积分数。一方面，砂芯应该足够坚固，以便在铸造过程中幸存下来。另一方面，铸造后的砂应该很容易提取。目前，在工业中，寻找成本效益高的配方来混合砂子和粘结剂类型需要繁琐的校准和专家的知识。这源于对所产生的砂芯的物理性质的敏感性的不完全理解。砂型粘结剂的特性。此外，即使在受控的射砂过程中，最终的砂芯也表现出不均质性，例如密度，这需要在设计过程中考虑到。在以前的工作中，我们介绍了一种基于X射线微计算机断层扫描和模拟紧实化的随机微结构模型的生成方法，作为进一步模拟研究的起点。在本工作中，我们改进了先前介绍的方法，以更好地适用于工业问题：首先，我们省去了耗时的形态膨胀，转而使用背景CAD模型。其次，我们利用现代图像处理工具包含了更多种类的真实砂形，利用手头的这一工具，我们模拟了这些微结构的强度、渗透率和导热系数，并将其与专用实验进行了比较，为《数字砂芯物理》奠定了基础。(C)2019爱思唯尔有限公司。保留所有权利。
In this work, we compare measurements of strength, permeability and thermal conductivity of blown anorganically bound sand cores to simulation results on digitally generated unit cell models resolving the fine sand grain-binder aggregate on the micrometer scale.The quality and operationality of sand cores used in foundry applications is strongly affected by different characteristics of the sand and binder used, for instance chemical composition, porosity, grain size distributions and binder volume fraction. On the one hand, sand cores should be strong enough to survive the casting process. On the other hand, after casting extracting the sand should be easy. Currently, in industry, finding cost-efficient recipes for mixing sand and binder types requires tedious calibration and expert's knowledge. This originates from an incomplete understanding of the sensitivity of the physical properties of the resulting sand core w.r.t. the sand-binder characteristics. Furthermore, even with a controlled sand shooting process, the final sand core exhibits a heterogeneity, for instance in density, which needs to be accounted for during the design process.In a previous work, we have introduced a method to generate stochastic microstructure models based on X-ray micro-computed tomography scans and simulated compactification, which serves as the starting point for further simulation studies.In this work, we improve the previously introduced method towards better applicability to industrial problems: Firstly, we dispense with the time-consuming morphological dilation and use background CAD models instead. Secondly, we include a broader variety of real sand shapes by utilizing modern image processing tools.With this tool at hand, we simulate strength, permeability and thermal conductivity on these microstructures, and subsequently compare those to dedicated experiments, laying the foundation for "Digital Sand Core Physics". (C) 2019 Elsevier Ltd. All rights reserved.