Pore elimination mechanisms during 3D printing of metals
Pore elimination mechanisms during 3D printing of metals
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DOI：
10.1038/s41467-019-10973-9
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发表时间：
2019-07-12
影响因子：
16.6
通讯作者：
Chen, Lianyi
中科院分区：
文献类型：
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作者：
Hojjatzadeh, S. Mohammad H.;Parab, Niranjan D.;Chen, Lianyi
激光粉床融合(LPBF)是一种3D打印技术，可以打印出具有复杂几何形状的金属零件，而不受传统制造路线的设计约束。然而，LPBF印刷的零件通常比传统方法印刷的零件含有更多的毛孔，这严重恶化了它们的性能。在这里，我们通过现场高速高分辨率同步辐射X射线成像实验和多物理模拟相结合，揭示了LPBF过程中气孔运动和消除的动力学和机理。我们发现，激光相互作用区域的高温度梯度所产生的高热毛细管力可以在LPBF过程中迅速消除熔池中的气孔。本文揭示的热毛细管力驱动的气孔消除机理可能指导3D打印方法的发展，以实现金属的无气孔3D打印。
Laser powder bed fusion (LPBF) is a 3D printing technology that can print metal parts with complex geometries without the design constraints of traditional manufacturing routes. However, the parts printed by LPBF normally contain many more pores than those made by conventional methods, which severely deteriorates their properties. Here, by combining in-situ high-speed high-resolution synchrotron x-ray imaging experiments and multi-physics modeling, we unveil the dynamics and mechanisms of pore motion and elimination in the LPBF process. We find that the high thermocapillary force, induced by the high temperature gradient in the laser interaction region, can rapidly eliminate pores from the melt pool during the LPBF process. The thermocapillary force driven pore elimination mechanism revealed here may guide the development of 3D printing approaches to achieve pore-free 3D printing of metals.