Microstructural evolution during sintering of copper particles studied by laboratory diffraction contrast tomography (LabDCT).
Microstructural evolution during sintering of copper particles studied by laboratory diffraction contrast tomography (LabDCT).
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DOI：
10.1038/s41598-017-04742-1
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发表时间：
2017-07-12
影响因子：
4.6
通讯作者：
Withers PJ
中科院分区：
文献类型：
--
作者：
McDonald SA;Holzner C;Lauridsen EM;Reischig P;Merkle AP;Withers PJ
通过颗粒重排、旋转、局部变形和扩散以及晶粒生长的组合，在高温下对松散或压实的颗粒体进行无压烧结。对这些过程如何促进粉末体致密化的理解仍然不成熟。在这里，我们报告了一项在延时研究中将实验室衍射对比断层扫描 (LabDCT) 的晶体成像能力与传统计算机断层扫描 (CT) 相结合的基础研究。在 1050°C 下烧结简单铜粉样品的过程中，我们能够在三维空间中无损地跟踪和区分这些过程。 LabDCT 量化颗粒旋转（精度 <0.05°）和晶粒生长，而吸收 CT 同时记录烧结颗粒的扩散和变形相关的形态变化。我们发现，对于高度协调的颗粒，颗粒旋转速率最低，并且在烧结过程中降低。因此，表面破碎颗粒的旋转比更高度协调的内部颗粒的旋转更大。观察到滚动（协作）和滑动粒子旋转。通过跟踪单个晶粒，首次对烧结过程中的晶粒生长/收缩动力学进行逐粒量化。观察到一种晶粒快速、异常的晶粒生长，而其他晶粒要么生长，要么逐渐消耗。
Pressureless sintering of loose or compacted granular bodies at elevated temperature occurs by a combination of particle rearrangement, rotation, local deformation and diffusion, and grain growth. Understanding of how each of these processes contributes to the densification of a powder body is still immature. Here we report a fundamental study coupling the crystallographic imaging capability of laboratory diffraction contrast tomography (LabDCT) with conventional computed tomography (CT) in a time-lapse study. We are able to follow and differentiate these processes non-destructively and in three-dimensions during the sintering of a simple copper powder sample at 1050 °C. LabDCT quantifies particle rotation (to <0.05° accuracy) and grain growth while absorption CT simultaneously records the diffusion and deformation-related morphological changes of the sintering particles. We find that the rate of particle rotation is lowest for the more highly coordinated particles and decreases during sintering. Consequently, rotations are greater for surface breaking particles than for more highly coordinated interior ones. Both rolling (cooperative) and sliding particle rotations are observed. By tracking individual grains the grain growth/shrinkage kinetics during sintering are quantified grain by grain for the first time. Rapid, abnormal grain growth is observed for one grain while others either grow or are consumed more gradually.
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影响因子：
4.7
作者：
King, A.;Reischig, P.;Ludwig, W.
通讯作者：
Ludwig, W.
DOI：
10.1016/j.msea.2009.02.009
发表时间：
2009-05-20
影响因子：
6.4
作者：
McDonald, S. A.;Motazedian, F.;Withers, P. J.
通讯作者：
Withers, P. J.
影响因子：
6
作者：
McDonald, SA;Schneider, LCR;Withers, PJ
通讯作者：
Withers, PJ
影响因子：
4
作者：
BERRY, RS;BERNHOLC, J;SALAMON, P
通讯作者：
SALAMON, P
影响因子：
9.4
作者：
McKenna, I. M.;Poulsen, S. O.;Voorhees, P. W.
通讯作者：
Voorhees, P. W.