摘要
利用尿素分解的均相沉淀法制得了球形 Al(OH)_3颗粒。影响颗粒形成、尺寸及其分布的主要因素为加热温度和沉淀时间等。球形 Al(OH)_3颗粒中含有[SO_4^(2-)],需在850℃以上开始分解。分解时,首先形成γ-Al_2O_3,比表面积增加,并在1000℃左右达最大值。此后α-Al_2O_3开始形成,比表面积下降。不同温度分解后的粉料烧结试验表明,α-Al_2O_3比γ-Al_2O_3具有更好的烧结性。另外,Al(OH)_3颗粒越小,分解后的Al_2O_3颗粒也越小,其烧结性能越好。
Spherical aluminum hydroxide particles have been prepared by homogeneous pre-cipitation combined with urea decomposition in solution.The experimental results showthat heating temperature,and holding time are the main factors affecting the for-mation,size and size distribution of the spherical particles.SO_4^(2-) is involved in thealuminum hydroxide particles and decomposes above 850℃.During decomposition,γ-Al_2O_3 can be formed first and the specific area of the powder increased,the max-imum of surface area can be obtained around 1000℃,and above 1000℃,α-Al_2O_3formed and surface area decreased,α-Al_2O_3 has better sinterability than γ-Al_2O_3,andthe less the Al(OH)_3 particle size,the less the Al_2O_3 particle size obtained,as wellas the better its sinterability.
出处
《无机材料学报》
SCIE
EI
CAS
CSCD
北大核心
1992年第2期161-167,共7页
Journal of Inorganic Materials
关键词
陶瓷
热分解
氢氧化铝
均相沉淀
Homogeneous precipitation
Spherical particles
Thermal decomposition
Aluminum hydroxide
