论文部分内容阅读
以ZrOCl2·8H2O和Y(NO3)3·6H2O为原料,采用共沉淀法合成纳米ZrO2-8wt%Y2O3(8YSZ)陶瓷粉末。利用XRD,SEM,TEM等方法研究纳米8YSZ粉末热处理后相结构、晶粒尺寸和形貌的变化,并分析纳米8YSZ粉末的晶体生长行为。结果表明:凝胶化反应的pH值(9(11)对纳米8YSZ粉末的相结构无明显影响,不同pH值合成的8YSZ纳米粉末在1000℃温度范围内热处理2h后都始终保持单一的四方相结构,在1200℃热处理2h后,仅有少量四方相转变为单斜相。随热处理温度的升高晶粒尺寸逐渐增大。由于晶体生长机制不同,纳米8YSZ粉末的晶粒生长活化能在低温区和高温区不同,均远低于微米级3YSZ材料的晶粒生长活化能(580kJ/mol)。
ZrOCl2 · 8H2O and Y (NO3) 3 · 6H2O were used as raw materials to synthesize ZrO2-8wt% Y2O3 (8YSZ) ceramic powders by coprecipitation method. The phase structure, grain size and morphology of the 8YSZ powder after heat treatment were studied by XRD, SEM and TEM. The crystal growth behavior of the 8YSZ powder was analyzed. The results showed that the pH value of gelled reaction (9 (11)) had no significant effect on the phase structure of 8YSZ nano-powders. The 8YSZ nano-powders synthesized at different pHs kept a single tetragonal phase after heat treatment at 1000 ℃ for 2h Structure, after heat treatment at 1200 ℃ for 2h, only a small amount of tetragonal phase transitions to monoclinic phase.With the increase of the heat treatment temperature, the grain size gradually increases.Due to the different crystal growth mechanism, the grain growth activation energy of nano-8YSZ powder is lower at low temperature Different from the high temperature region, the grain growth activation energy (580 kJ / mol) of micron-grade 3YSZ material is much lower.