Zhao Di, Liu Yuan, Shen Zhonglin, Liu Haifang, Guo Yinuo, Li Xiang, Dong Dong, Jiang Hao, Liu Congcong, Yang Peixin, Zhang Jun, Liu Lin, Zhang Chengyu, Fu Hengzhi
State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi'an 710072, P. R. China.
Nano Lett. 2022 Mar 23;22(6):2405-2411. doi: 10.1021/acs.nanolett.2c00116. Epub 2022 Mar 8.
Porous ceramics possess great application potential in various fields. However, the contradiction between their pores and their strength have significantly hampered their applications. In this study, we present a simple directional solidification process that relies on its in situ pore forming mechanism to fabricate AlO/YAlO/ZrO porous eutectic ceramic composites with a highly dense and nanostructured eutectic skeleton matrix and a lotus-type porous structure. The flexural strength of this porous ceramic composite with a porosity of 34% is 497 MPa at ambient temperature, which is a new record of the strength of all current porous ceramics. This strength can remain at 324 MPa when the temperature increases up to 1773 K because of its refined lamellar structure and strong bonding interface. We demonstrate an interesting application of the directional solidification in efficiently preparing the ultrahigh-strength porous ceramic with high purity. The findings will open a window to the strength of porous ceramics.
多孔陶瓷在各个领域都具有巨大的应用潜力。然而，其孔隙率与强度之间的矛盾严重阻碍了它们的应用。在本研究中，我们提出了一种简单的定向凝固工艺，该工艺依靠其原位成孔机制来制备具有高密度和纳米结构共晶骨架基体以及莲花型多孔结构的AlO/YAlO/ZrO多孔共晶陶瓷复合材料。这种孔隙率为34%的多孔陶瓷复合材料在室温下的抗弯强度为497MPa，这是目前所有多孔陶瓷强度的新纪录。由于其细化的层状结构和强结合界面，当温度升高到1773K时，该强度仍可保持在324MPa。我们展示了定向凝固在高效制备高纯度超高强度多孔陶瓷方面的有趣应用。这些发现将为多孔陶瓷的强度打开一扇窗口。
