陳化對Al_2O_3-ZrO_2共沉粉末之相轉換與燒結行為的影響

Effects of Aging Treatment on the Phase Transformation and Sintering Behaviors of Coprecipitated AI_2O_3-ZrO_2 Powders

陳智成(C. C. Chen) ； 顏富士(F. S. Yen)

《鑛冶：中國鑛冶工程學會會刊》 38卷3期 (1994/09) Pp. 135-143

摘要

本研究以化學共沉法製備ZTA陶瓷複合材料，並探討陳化對ZTA複合材料之相轉換與燒結行為的影響。在製備過程中，共沉物先經陳化處理，陳化處理是在室溫，pH=9的鹼性溶液中進行。在不同陳化條件下，燒結體之ZrO_2顆粒可產生在Al_2O_3晶粒內或晶粒間，且陳化處理也會影響t-ZrO_2的數量。實驗結果也顯示，陳化處理可減少燒結體晶粒内ZrO_2顆粒的數量與煆燒粉末的凝聚體強度，這兩項作用似乎可以增進ZTA陶瓷體燒結密度。經由適當的陳化過程，可獲得相對密度＞99%，且含晶粒間ZrO_2的ZTA燒結體。

並列摘要

In this study ZTA and SiCw/ZTA ceramic composites were prepared from powders obtained by chemical coprecipitation method. Effects of gel aging on the characteristics of zirconia-toughened alumina (ZTA) composites were investigated. The coprecipitates were aged in an aqueous solution of pH = 9 at room temperature. The occurrence of either intra- or inter-granular ZrO_2 particles in the AI_2O_3 matrix depended on the aging condition, which also affected the content of tetragonal ZrO_2 (t-ZrO_2). Aging treatment decreased the amount of intragranular ZrO_2, as well as the agglomerate strength of calcined powders, both of which seemed to impove the sintered densities of ZTA ceramic bodies. Through suitable aging process, sintered ZTA specimens with relative density ＞ 99% and intergranular ZrO_2 particles can be fabricated.