On the measurement of relative powder-bed compaction density in powder-bed additive manufacturing processes
On the measurement of relative powder-bed compaction density in powder-bed additive manufacturing processes
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DOI：
10.1016/j.matdes.2018.06.030
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发表时间：
2018-10-05
影响因子：
8.4
通讯作者：
Toyserkani, Ehsan
中科院分区：
文献类型：
--
作者：
Ali, Usman;Mahmoodkhani, Yahya;Toyserkani, Ehsan
文献中的实验研究已经将粉末床压实密度确定为控制增材制造部件质量的重要参数。例如，在激光粉末床熔合（LPBF）中，粉末床压实密度直接影响粉末的有效导热率，从而影响熔池中的温度分布。在这项研究中，这个物理参数在LPBF构建隔室测量使用一种新的方法。当使用Hastelloy X时，UV可固化聚合物用于在粉末床隔室上的各个位置处结合粉末床颗粒。然后使用纳米计算机断层扫描（CT）系统以高分辨率扫描样品，以获得相对粉末床压实密度的估计。得出的结论是，由于重涂器之间的相互作用以及在整个构建隔室中在重涂器之前累积的粉末体积的变化，相对粉末床压实密度沿着重涂器移动方向减小（从66.4%减小到52.4%）。粉末床压实密度的这种变化也影响最终印刷部件的密度和表面粗糙度。结果表明，在重涂机运动的方向上，沿着构造床，部件密度和表面质量分别降低约0.25%和约20%。(C)2018爱思唯尔有限公司版权所有
Experimental studies in the literature have identified the powder-bed compaction density as an important parameter, governing the quality of additively manufactured parts. For example, in laser powder-bed fusion (LPBF), the powder-bed compaction density directly affects the effective powder thermal conductivity and consequently the temperature distribution in melt pool. In this study, this physical parameter in a LPBF build compartment is measured using a new methodology. A UV curable polymer is used to bind powder-bed particles at various locations on the powder-bed compartment when Hastelloy X was used. The samples are then scanned using a nano-computing tomography (CT) system at high resolution to obtain an estimation of the relative powder-bed compaction density. It is concluded that due to the interaction between the recoater and the variation in the powder volume accumulated ahead of the recoater across the build compartment, the relative powder-bed compaction density decreases along the recoater moving direction (from 66.4% to 52.4%.). This variation in the powder-bed compaction density affects the density and surface roughness of the final printed parts that is also investigated. Results show that the part density and surface quality decrease similar to 0.25% and similar to 20%, respectively, along the build bed in direction of the recoater motion. (C) 2018 Elsevier Ltd. All rights reserved.