Abstract Cold sintering is a promising route towards the manufacturing of dense ceramics at mild processing conditions, but our poor understanding of the process has prevented the wider spread of this attractive densification approach. Using nanovaterite powders with well-defined multiscale morphology, we perform in-situ X-Ray tomography on compacts subjected to controlled mechanical load and quantify the multiscale deformation processes responsible for the water-assisted cold sintering of this powder with the help of instrumented indentation experiments at the micro- and nano-scale. Our results reveal the crucial effect of water in promoting the macroscopic densification process and highlight the dominant role of the nanoparticle network inside agglomerates in controlling the cold sintering of compacts at high mechanical loads. By providing new insights into the deformation processes responsible for the densification effect, this study can potentially guide the discovery of novel chemical compositions and particle morphologies that can be more easily densified through room-temperature cold sintering with water.

中文翻译：

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纳米球霰石压坯冷烧结过程中的多尺度变形过程

摘要 冷烧结是在温和的加工条件下制造致密陶瓷的一种很有前途的途径，但我们对该过程的了解不足阻碍了这种有吸引力的致密化方法的更广泛传播。使用具有明确定义的多尺度形态的纳米球霰石粉末，我们对承受受控机械载荷的压块进行原位 X 射线断层扫描，并在仪器压痕实验的帮助下量化负责这种粉末的水辅助冷烧结的多尺度变形过程在微米和纳米级。我们的结果揭示了水在促进宏观致密化过程中的关键作用，并突出了团聚体内部的纳米颗粒网络在控制高机械载荷下压块冷烧结方面的主导作用。