CHAO Lumen, HOU Yudong, ZHENG Mupeng, ZHU Mankang
(Beijing University of Technology, Beijing 100124, China)
Abstract: In this work, the high activity NaNbO3 nano-powders have been synthesized by high-energy ball milling method, and the related mechanochemical mechanism and densification sintering behavior have been investigated in detail. The study revealed that by tailoring the rotating speed and ball-to-powder weight ratio, the pure perovskite NaNbO3 nano-powders can be synthesized within 1.5 h by using tungsten carbide ball as grinding media. Compared with the literature data, the synthesis time of pure NaNbO3 has been significantly shortened, which can be attributed to the high impact energy (457 mJ/hit) in optimal experimental conditions. Further, the densification sintering behavior and electrical properties have been investigated. It was found that the ceramic body derived from nano-powders presents high dense fine grained structure, and the dielectric property in a wide temperature region was improved greatly. These results suggested that high-energy ball milling method not only is conductive to synthesize highly active nano-powders, but also is in favor of preventing the volatilization of alkali metals,showing potential application in building high-performance alkaline niobate based multilayer ceramic electronic components.
Key words: synthesis methods; microstructure; densification; dielectric properties