Temperature dependence of constitutive behaviour for solid-state sintering of alumina
Temperature dependence of constitutive behaviour for solid-state sintering of alumina
复制标题
氧化铝固态烧结本构行为的温度依赖性
DOI：
10.1016/j.actamat.2004.03.008
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发表时间：
2004
期刊：
影响因子：
9.4
通讯作者：
J. Rödel
中科院分区：
文献类型：
--
作者：
R. Zuo;J. Rödel
一个不连续的热锻方法是在这项研究中，以提取的温度依赖性的本构烧结参数氧化铝。单轴粘度和烧结应力都实验获得的密度和温度的各向同性的微观结构的函数。粘度的活化能被确定为约480 kJ/mol的装置的Arrhenius型图纳入在不同温度下的晶粒尺寸数据。结果表明，氧化铝在小载荷下烧结过程中的蠕变和致密化均为晶界扩散控制的动力学过程。单轴粘度和体相粘度具有相同的温度依赖性，表明粘滞泊松系数与温度无关。多孔压块的烧结应力被实验确定为与温度无关，但与晶粒尺寸成反比，与理论预测一致。
A discontinuous hot forging approach was employed in this study in order to extract the temperature dependence of the constitutive sintering parameters for alumina. Uniaxial viscosity and sintering stress were both experimentally obtained as functions of density and temperature for an isotropic microstructure. The activation energy for the viscosities was determined to be approximately 480 kJ/mol by means of an Arrhenius-type plot incorporating the grain size data at varying temperatures. It was indicated that creep and densification during sintering of alumina under a small uniaxial load were both grain boundary diffusion controlled kinetic processes. The same temperature dependence of uniaxial and bulk viscosities was demonstrated, indicating that the viscous Poisson's coefficient is temperature-independent. The sintering stress of a porous compact was experimentally identified as independent of temperature, but inversely proportional to grain size, in agreement with theoretical predictions.