SUN Xi 1, MA Jingtao 2, DENG Changsheng 2, ZHAO Xingyu 2, HAO Shaochang 2, LIU Bing 2
(1. Nuclear fuel and material research department, Central research institute of state power investment corporation, Beijing 102209, China; 2. State Key Laboratory of New Ceramics and Fine Processing, Collaborative Innovation Center of Advanced Nuclear Energy Technology, Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, China)
Abstract: The fabrication process of ZrCO composite ceramic microspheres was studied through internal gelation combined with carbothermic reduction with fructose as carbon source. The effects of sintering atmosphere and sintering temperature on composition, surface morphology, microstructure and mechanical properties of the ZrCO composite ceramic microspheres were systematically examined. It was found that the ZrCO ceramic microspheres sintered at 1550 ℃ with argon containing different concentrations of CO had very smooth surface and high degree of sphericity, but the carbothermic reduction of ZrO2 was inhibited by the introduction of CO in the sintering atmosphere. Although the carbothermal reduction reaction could be further promoted by increasing the sintering temperature, but the fractural strength of the sintered microspheres was gradually decreased.
Key words: ZrCO ceramic microspheres; carbothermic reduction; sintering atmosphere; sintering temperature