Wu Angxuan, Zhu Yuchen, Xu Chen, Yan Nianping, Zhao Xuetong, Wang Xilin, Jia Zhidong
Engineering Laboratory of Power Equipment Reliability in Complicated Coastal Environments, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China.
Institute of Materials, China Academy of Engineering Physics, Mianyang 621907, China.
Materials (Basel). 2023 Feb 13;16(4):1544. doi: 10.3390/ma16041544.
Arc floating in surface flashover can be controlled by reducing the interfacial charge-transfer resistance of ceramics. However, thus far, only a few studies have been conducted on methods of treating ceramic surfaces directly to reduce the interfacial charge-transfer resistance. Herein, we explore the flash sintering behavior of a ceramic surface (3 mol% yttria-stabilized zirconia (3YSZ)) onto which loose metal (iron) powder was spread prior to flash sintering at room temperature (25 °C). The iron powder acts as a conductive phase that accelerates the start of flash sintering while also doping the ceramic phase during the sintering process. Notably, the iron powder substantially reduces the transition time from the arc stage to the flash stage from 13.50 to 8.22 s. The surface temperature (~1600 °C) of the ceramic substrate is sufficiently high to melt the iron powder. The molten metal then reacts with the ceramic surface, causing iron ions to substitute Zr ions and promoting rapid densification. The YSZ grains in the metal-infiltrated area grow exceptionally fast. The results demonstrate that spreading metal powder onto a ceramic surface prior to flash sintering can enable the metal to enter the ceramic pores, which will be of significance in developing and enhancing ceramic-metal powder processing techniques.
通过降低陶瓷的界面电荷转移电阻，可以控制表面闪络中的电弧。然而，到目前为止，关于直接处理陶瓷表面以降低界面电荷转移电阻的方法的研究还很少。在此，我们探索了一种陶瓷表面（3 mol% 氧化钇稳定氧化锆 (3YSZ)）在室温 (25 °C) 下进行快速烧结之前，在其上散布疏松金属（铁）粉后的快速烧结行为。铁粉作为导电相，加速了快速烧结的开始，同时在烧结过程中也对陶瓷相进行了掺杂。值得注意的是，铁粉将从电弧阶段到快速阶段的过渡时间从13.50秒大幅缩短至8.22秒。陶瓷基板的表面温度（约1600°C）足够高，足以熔化铁粉。然后，熔融金属与陶瓷表面发生反应，使铁离子取代Zr离子并促进快速致密化。金属渗入区域的YSZ晶粒生长异常迅速。结果表明，在快速烧结之前将金属粉末散布在陶瓷表面上，可以使金属进入陶瓷孔隙，这对于开发和改进陶瓷-金属粉末加工技术具有重要意义。
