In-situ digital image correlation and thermal monitoring in directed energy deposition additive manufacturing
In-situ digital image correlation and thermal monitoring in directed energy deposition additive manufacturing
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DOI：
10.1364/oe.416659
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发表时间：
2021-03-29
期刊：
影响因子：
3.8
通讯作者：
Paquit, Vincent
中科院分区：
文献类型：
--
作者：
Haley, James;Leach, Clay;Paquit, Vincent
如在焊接中一样，定向能量沉积（DED）增材制造（AM）产生与用于沉积的扫描图案的复杂性相称的复杂残余应力和变形。迄今为止，测量复杂几何形状的DED变形仅在后处理中实现，丢弃了导致最终材料状态的复杂热机械历史。在这项工作中，环绕立体声数字图像相关（DIC）是用来3D地图的表面和应变张量原位在粉末吹激光DED系统。然后将红外热成像投射到这些表面上，以记录打印部件的完整热机械历史。DIC对DED AM提出了独特的挑战，因为在沉积开始时不存在部件，这（a）防止应用适当的散斑图案，并且（B）拒绝用户零应变参考系。这些问题的解决方案，提出了他们的局限性探讨。总之，这项工作提出了一个相对低成本的解决方案，以监测和优化独特的时间文物所引起的复杂的扫描策略，这是以前无法获得的。
As in welding, directed energy deposition (DED) additive manufacturing (AM) generates complex residual stresses and distortions commensurate with the complexity of the scan pattern used for deposition. To date, measuring DED distortions on complex geometries has only been achieved post process, discarding the complex thermomechanical history that leads to that final material state. In this work, surround stereo digital image correlation (DIC) is used to 3D map surfaces and strain tensors in-situ in a powder-blown laser DED system. Infrared thermography is then projected onto these surfaces to record the full thermomechanical history of printed parts. DIC presents a unique challenge to DED AM, as no part exists at the beginning of deposition, which (a) prevents application of an appropriate speckle pattern and (b) denies the user a zero strain reference frame. Solutions to these problems are proposed and their limitations explored herein. In sum, this work presents a relatively low-cost solution to monitoring and optimizing the unique temporal artifacts induced by complex scan strategies that was previously unobtainable.