( 1. 中南大學(xué) 粉末冶金國家重點實驗室， 長沙 410083；
2. 湖南大學(xué) 化學(xué)化工學(xué)院，長沙 410082)
摘 要: 采用非線性加熱法煅燒鋯、 釔的草酸鹽前驅(qū)體， 制備了8%Y2O3(摩爾分?jǐn)?shù))穩(wěn)定ZrO2(8YSZ)超細(xì)粉末。 研究了金屬離子與草酸的摩爾比及熱處理方法對8YSZ的晶體結(jié)構(gòu)、 晶粒大小、 形貌、 比表面積、 粒子團(tuán)聚的影響。 通過改變不同溫度范圍的加熱速度來優(yōu)化草酸鹽前驅(qū)體熱分解工藝。 采用優(yōu)化前驅(qū)體熱分解工藝即非線性加熱法， 于600~700 ℃煅燒得到的粉末為等軸晶形， 粒子大小在90~100 nm之間， 粒子間僅有較弱的軟團(tuán)聚。 煅燒過程晶粒生長動力學(xué)的研究表明： 當(dāng)煅燒溫度高于700 ℃時， 晶粒生長的質(zhì)量傳輸受晶粒擴散過程控制； 低于700 ℃時， 晶粒生長的質(zhì)量傳輸由表面擴散過程控制。
關(guān)鍵字: 釔穩(wěn)定氧化鋯； 非線性加熱法； 草酸鹽前驅(qū)體； 晶粒生長
（ 1. State Key Laboratory for Powder Metallurgy,
Central South University, Changsha 410083, China;
2. College of Chemistry and Chemical Engineering,
Hunan University, Changsha 410082, China）
Abstract: Ultrafine 8%(mole fraction) yttria-stabilized zirconia (8YSZ) powder was prepared by nonlinear heating of the oxalate precursor of yttrium and zirconium ions. The effects of molar ratio of metal ions to H2C2O4, and thermal decomposition of precursor on the crystal structure, specific surface area, grain size and morphology of 8YSZ powder were studied. The thermal decomposition process of the oxalate precursor was optimized through varying heating rate in different temperature ranges. The powders produced through optimized thermal decomposition process (nonlinear heating method at 600-700 ℃), were weakly aggregated and equiaxial, with a narrow particle size distribution of 90-100 nm. The kinetic for grain growth during calcination process was investigated. The results show that grain growth is controlled by grain boundary or lattice diffusion with higher activation energy (192.92 kJ/mol) when temperature is above 700 ℃, or controlled by surface diffusion with lower activation energy (87.38 kJ/mol) when temperature is below 700 ℃.
Key words: yttria-stabilized zirconia; nonlinear heating method; oxalate precursor; grain growth
