Micro-CT for analysis of laser sintered micro-composites
Micro-CT for analysis of laser sintered micro-composites
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DOI：
10.1108/rpj-08-2019-0211
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发表时间：
2020-01
影响因子：
3.9
通讯作者：
J. R. Wingham;R. Turner;J. Shepherd;C. Majewski
中科院分区：
文献类型：
--
作者：
J. R. Wingham;R. Turner;J. Shepherd;C. Majewski
目的X射线计算机微断层扫描（micro-CT）在增材制造中作为确定打印部件的孔隙率和几何形状以及在某些情况下确定是否存在夹杂物或污染的方法得到了相对完善的应用。本文的目的是证明，微型CT也可以用来定量分析的均匀性的微型复合材料零件，在这种情况下，使用激光烧结（LS）。设计/方法/途径LS样本在聚酰胺12中制造，并结合和不结合不同尺寸的银磷酸盐玻璃添加剂。使用微CT扫描样品以确定它们的孔隙率和添加剂在整个体积中分散的均匀性。结果-这项工作表明，它是可能的，使用微CT来确定相关的信息，从同一扫描的孔隙度和添加剂分散。孔隙的分析揭示了打印部件的总体孔隙率，线性弹性断裂力学用于识别可能导致部件过早失效的任何孔隙。发现添加剂的分析在一定粒度以上是可能的，其中粒度分布用于识别银磷酸盐玻璃的任何附聚。颗粒位置还用于确定添加剂的完全空间随机性，作为分散的定量测量。实用意义-这表明，微CT是一种有效的方法，识别印刷部件内的孔隙率和添加剂团聚，这意味着它可以用于微复合材料的质量控制和验证打印前的聚合物/添加剂混合物的均匀性。独创性/价值-这被认为是第一个实例的微型CT被用来识别和分析激光烧结部分内的添加剂的分布。
Purpose X-Ray-computed micro-tomography (micro-CT) is relatively well established in additive manufacturing as a method to determine the porosity and geometry of printed parts and, in some cases, the presence of inclusions or contamination. This paper aims to demonstrate that micro-CT can also be used to quantitatively analyse the homogeneity of micro-composite parts, in this case created using laser sintering (LS). Design/methodology/approach LS specimens were manufactured in polyamide 12 with and without incorporation of a silver phosphate glass additive in different sizes. The specimens were scanned using micro-CT to characterise both their porosity and the homogeneity of dispersion of the additive throughout the volume. Findings This work showed that it was possible to use micro-CT to determine information related to both porosity and additive dispersion from the same scan. Analysis of the pores revealed the overall porosity of the printed parts, with linear elastic fracture mechanics used to identify any pores likely to lead to premature failure of the parts. Analysis of the additive was found to be possible above a certain size of particle, with the size distribution used to identify any agglomeration of the silver phosphate glass. The particle positions were also used to determine the complete spatial randomness of the additive as a quantitative measure of the dispersion. Practical implications This shows that micro-CT is an effective method of identifying both porosity and additive agglomeration within printed parts, meaning it can be used for quality control of micro-composites and to validate the homogeneity of the polymer/additive mixture prior to printing. Originality/value This is believed to be the first instance of micro-CT being used to identify and analyse the distribution of an additive within a laser sintered part.