Smirnov Andrey V, Kornyushin Maxim V, Kholodkova Anastasia A, Melnikov Sergey A, Stepanov Artem D, Fesik Elena V, Mnatsakanyan Vilen V, Smirnov Anton, Ivakin Yurii D
Mobile Solutions Engineering Center, MIREA-Russian Technological University, 119454 Moscow, Russia.
Materials Science Department, Moscow Polytechnic University, 107023 Moscow, Russia.
Materials (Basel). 2023 Jan 1;16(1):408. doi: 10.3390/ma16010408.
The influence of the method of applying the activating additive ammonium chloride and its concentration on the density and microstructure of zinc oxide ceramic obtained by cold sintering at 244 °C was investigated. The activating agent was applied by two methods: impregnation and subsequent autoclave treatment. When the powder was activated by the impregnation method, the crystal sizes remained at the initial level of 0.17-0.19 μm. After the autoclave treatment, the crystal sizes increased to 0.31-0.53 μm. Samples of cold sintering ZnO with relative density up to 0.96 and average grain sizes 0.29-0.86 μm were obtained. ZnO powders and ceramic samples were analyzed using SEM, TGA/DSC, and XRD to reveal the effect of the powder activation method and cold sintering conditions on the material microstructure. The effect of ammonium chloride concentration on grain growth and microstructure of ceramic samples is shown. It was found that the average grain size of ceramic samples with an increase in additive concentration passes through a minimum. In cold sintering of the autoclave activated powder, the effect of reducing the average grain size was observed. The results of this work are discussed on the basis of the idea of the solid-phase mobility of the crystal structure arising when interacting with an aqueous medium.
研究了活化添加剂氯化铵的施加方法及其浓度对在244℃下通过冷烧结获得的氧化锌陶瓷的密度和微观结构的影响。活化剂通过两种方法施加：浸渍和随后的高压釜处理。当通过浸渍法活化粉末时，晶体尺寸保持在0.17 - 0.19μm的初始水平。经过高压釜处理后，晶体尺寸增加到0.31 - 0.53μm。获得了相对密度高达0.96且平均晶粒尺寸为0.29 - 0.86μm的冷烧结ZnO样品。使用扫描电子显微镜（SEM）、热重/差示扫描量热仪（TGA/DSC）和X射线衍射仪（XRD）对ZnO粉末和陶瓷样品进行分析，以揭示粉末活化方法和冷烧结条件对材料微观结构的影响。展示了氯化铵浓度对陶瓷样品晶粒生长和微观结构的影响。发现随着添加剂浓度的增加，陶瓷样品的平均晶粒尺寸先减小后增大。在高压釜活化粉末的冷烧结中，观察到平均晶粒尺寸减小的效果。基于与水性介质相互作用时晶体结构的固相迁移率这一概念，对这项工作的结果进行了讨论。
