SiO2对溶胶-凝胶法制备的ZrO2纤维相变和微观组织的影响∗

摘要

Zirconia fibers containing different amount of silica are prepared using zirconium oxychloride,hydro-gen peroxide and silica sol as the raw materials and by sol-gel method.SEM,XRD,DTA,FT-IR,29 Si NMR and TEM are used to characterize the zirconia-silica fibers.It has been found that silica can significantly stabilize the tetragonal ZrO2 phase,inhibiting its phase transformation to the monoclinic phase.As the consequence,the formation of sheath-core structure in the zirconia-silica fibers has been prevented.Silica can also effectively in-hibit the grain growth,resulting in crack-free,transparent,dense and flexible ceramic fibers.%通过氧氯化锆与过氧化氢的反应得到氧化锆溶胶，与 SiO2溶胶混合后，制备了不同 SiO2含量的氧化锆纤维，采用SEM、XRD、DTA、FT-IR、29 Si NMR、TEM等对纤维相组成和微观结构进行了系统研究。结果表明，少量SiO2可以显著提高四方相ZrO2的稳定性，抑制单斜相的形成，避免纤维“皮芯结构”的形成。此外 SiO2可以有效抑制晶粒长大，从而达到细晶的作用，获得无表面缺陷、致密、柔性的ZrO2纤维。