Laboratory for Materials and Structures, Institute of Innovative Research, Tokyo Institute of Technology, R3-23 4259 Nagatsuta, Midori, Yokohama, 226-8503, Japan.
Department of Materials Science and Technology, Nagaoka University of Technology, 1603-1, Kamitomioka, Nagaoka, Niigata, 940-2188, Japan.
Sci Rep. 2017 Sep 11;7(1):11106. doi: 10.1038/s41598-017-11667-2.
Sintering is a common process during which nanoparticles and microparticles are bonded, leading to the shrinkage of interstitial pore space. Understanding morphological evolution during sintering is a challenge, because pore structures are elusive and very complex. A topological model of sintering is presented here, providing insight for understanding 3-D microstructures observed by X-ray microtomography. We find that the topological evolution is described by Euler characteristics as a function of relative density. The result is general, and applicable not only to viscous sintering of glasses but also to sintering of crystalline particles. It provides criteria to distinguish the stages of sintering, and the foundations to identify the range of applicability of the methods for determining the thermodynamic driving force of sintering.
烧结是一种常见的过程，在此过程中纳米颗粒和微颗粒结合在一起，导致间隙孔空间收缩。理解烧结过程中的形态演变是一个挑战，因为孔结构难以捉摸且非常复杂。本文提出了一种烧结的拓扑模型，为理解 X 射线微断层摄影术观察到的 3D 微观结构提供了深入的见解。我们发现，拓扑演变可以用欧拉特征来描述，作为相对密度的函数。结果是通用的，不仅适用于玻璃的粘性烧结，也适用于晶体颗粒的烧结。它提供了区分烧结阶段的标准，并为确定烧结热力学驱动力的方法的适用范围奠定了基础。
