添加燃烧合成晶种SPS烧结Ybα-SiAlON陶瓷

Fabrication of Yb α-SiAlON Ceramics by SPS with Crystal Seeds Prepared through Combustion Synthesis

通过燃烧合成技术制备单相Yb α-SiAION粉体,然后作为晶种添加到原料中利用SPS技术快速烧结出致密Yb α-SiAION陶瓷.对SPS烧结过程中试样的致密化、相转变和形貌发育进行了研究,并探讨了添加晶种对烧结产物相组成和微观形貌的影响.实验结果表明, SPS可使试样迅速完成致密化过程,适当的烧结温度和保温时间可以促进相转变和晶粒发育. 添加晶种,不仅促进了相转变过程,而且可以在烧结体内获得柱状晶,有助于改善材料的韧性.

Single-phase Yb α-SiAlON was prepared through combustion synthesis, then the as-synthesized powder was added as crystal seeds for fabrication of Yb α-SiAlON ceramics by SPS. The densification process, phase transformation, as well as microstructure development were studied, and effects of seed addition on the phase composition and microstructure of the sintered ceramics were also discussed. The experimental results show that the samples can be densified very quickly by SPS, and proper temperature and dwelling time are beneficial to phase transformation and grain growth. Seed addition accelerates the phase transformation as well as results in the formation of rod-like crystals, which is helpful to improve the toughness of ceramics.