摘要
从实验得到的平均粒径为0.35μm和2.5μm的α-Al_2O_3在不同升温速率下的烧结曲线出发,以Johnson恒速升温烧结动力学公式为基础,研究了升温速率及颗粒尺寸对有效激活能的影响。发现两种粒径样品的有效烧结激活能不是定值,呈现出随温度升高而降低的趋势;两种升温速率下,0.35m样品有效激活能具有一致性,而2.5μm样品只在高温阶段具有一致性;相同升温速率情况下,粒径小的样品的有效激活能受升温速率的影响较大。
On the basis of the sintering curves at different constant heating rates for α-Al2O3 with the mean particle size of 0.35, m and 2.5, m respectively, the influences of heating rates and particle size on the effective activation energy were investigated according to the theory of sintering kinetics at constant heating rates put forward by Johnson. It is found that the effective activation energy is not a constant, which decreases with the rise of the temperature. Under two heating rates, the effective activation energy of 0.35 μm sample is almost the same, however, which complies with each other only at higher temperature for 2.5 μm specimen. At the same time, it is discovered that the effective activation energy of the sample with the smaller particle size is sensitive to the heating speeds.
出处
《中国陶瓷》
CAS
CSCD
北大核心
2007年第12期49-51,28,共4页
China Ceramics
基金
青岛市自然科学基金
(项目编号:05-1-JC-89)
关键词
Α-AL2O3
有效激活能
粒径
升温速率
α-Al2O3 effective activation energy, particle size, heating rates
