为改善氧化铝陶瓷的韧性,以Al2O3、SiO2和AlF3·3H2O为原料,原位合成了莫来石晶须-氧化铝复合体系.探讨了AlF3·3H2O加入量(质量分数分别为2.9％、9.1％和16.6％)和热处理温度(1 400、1 500和1 600 ℃)对在Al2O3为80％ ～ 90％(ω)的粉体中原位合成莫来石晶须的影响,并研究了莫来石晶须的生长机制.结果表明:原位合成莫来石晶须-氧化铝复合体系的最佳工艺条件是AlF3·3H2O加入量为9.1％(ω),热处理条件为1 600℃保温5h;生成的莫来石晶须长度可达50 μm,长径比可达25;莫来石晶须的原位生长遵循气-固(VS)机制.
In order to improve the toughness of alumina ceramics,mullite whisker-alumina composites were in-situ synthesized using Al2O3,SiO2 and AlF3 · 3H2O as starting materials.The influences of the AlF3 3H2O additions (2.9％,9.1％,and 16.6％,by mass percent,the same hereinafter) and firing temperatures (1 400,1 500,and 1 600 ℃) on the in-situ synthesis of mullite whiskers in Al2O3 powder (Al2O3 content 80％ -90％) were studied.The in-situ growth mechanism of mullite whiskers was investigated as well.The resuits show that the optimum condition for preparing mullite whisker-alumina composite is as follows:9.1％ of AlF3 · 3H2O as additive,firing temperature of 1 600 ℃,and soaking time of 5 h.The synthesized mullite whiskers have an average length of 50 μm and a high length to diameter ratio of 25.The Vapor-Solid (VS) mechanism dominates the in-situ growth of mullite whiskers.
参考文献
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%