采用沉淀法以Al(NO3)3·9H2O和NH3·H2O为原料制备了Al(OH)3干凝胶,经过高温煅烧合成纳米级的α-Al2O3粉末,研究了不同的Al(OH)3干凝胶样品的TG/DTA变化和煅烧过程中亚稳态Al2O3的相变过程.试验证明,Al(OH)3干凝胶中NH4NO3和α-Al2O3籽晶的存在使θ→α成核势垒降低,从而使得相变温度也降低.NH4NO3的存在使θ-Al2O3→α-Al2O3的相变温度降低了40℃;NH4NO3和2wt%α-Al2O3籽晶的双重作用则使θ→α的相变温度约降低220℃.制备出的α-Al2O3粉末,粒径分布均匀,无明显团聚,近似六方球形,平均粒径为70nm.
参考文献
[1] | Zhang Mei Ge .The progress of technology of the superpure alumina synthesis[J].Journal of functional materials,1993,24(02):187-191. |
[2] | 林元华,张中太,黄传勇,唐子龙,陈清明.前驱体热解法制备高纯超细α-Al2O3粉体[J].硅酸盐学报,2000(03):268-271. |
[3] | Alphonse P;Courty M .Structure and thermal behavior of nanocrystalline boehmite[J].Thermochimica Acta: An International Journal Concerned with the Broader Aspects of Thermochemistry and Its Applications to Chemical Problems,2005(1/2):75-89. |
[4] | Vaidya SD.;Thakkar NV. .Study of phase transformations during hydration of rho alumina by combined loss on ignition and X-ray diffraction technique[J].The journal of physics and chemistry of solids,2001(5):977-986. |
[5] | WU Yu Cheng;SONG Zhan Ya;YANG Ye .The study of α alumina phase transformation and the control of phase transformation[J].Rare Metal,2004,28(06):1043-1048. |
[6] | Carty W M;Senapati U .[J].JOURNAL OF THE AMERICAN CHEMICAL SOCIETY,1998,81(01):3-20. |
[7] | Li J G;Sun X D .Synthesis and sintering behavior of a nanocrystallineα-Al2O3 powder[J].Acta Materialia,2000,48:103-3112. |
[8] | ZHU Lu Bing.Physics of surface and interface[M].天津:天津大学出版社,1992:173. |
上一张
下一张
上一张
下一张
计量
- 下载量()
- 访问量()
文章评分
- 您的评分:
-
10%
-
20%
-
30%
-
40%
-
50%