Sintering of Alumina in Microwave‐Induced Oxygen Plasma
Sintering of Alumina in Microwave‐Induced Oxygen Plasma
复制标题
DOI：
10.1111/j.1151-2916.1996.tb08096.x
复制
发表时间：
1996-12
影响因子：
3.9
通讯作者：
H. Su;D. Johnson
中科院分区：
文献类型：
--
作者：
H. Su;D. Johnson
在微波诱导的氧等离子体中烧结小圆柱形管，在可调谐的单模腔中引发和维持。温度和收缩测量的标本，分别使用光纤温度计黑体传感器和一个温度计。通过等离子体烧结实验和常规快速加热烧结实验，得到了氧化铝陶瓷在等离子体中烧结的活化能。铝合金沿着晶界的扩散被认为是主要的烧结机制，传统烧结的平均活化能为488 ± 20 kj/mol，等离子烧结的平均活化能为468 ± 20 kj/mol。在等离子体中烧结的试样与在相同的温度-时间偏移和氧气压力下在常规炉中烧结的试样的比较显示出由于等离子体的非热效应。为了进一步探索这种非热效应，进行了不同氧分压等离子体烧结实验。这种非热效应是由于等离子烧结过程中铝间隙浓度的增加而引起的。烧结数据进行了解释，使用组合阶段烧结模型。
Small cylindrical tubes were sintered in a microwave- induced oxygen plasma, initiated and sustained inside a tunable, single-mode cavity. Temperature and shrinkage measurements of the specimens were achieved using an optical-fiber thermometer black-body sensor and a dilatometer, respectively. Sintering experiments at constant heating rate were accomplished to obtain the activation energy for sintering of alumina in the plasma and in a conventional rapid-heating furnace. Diffusion of aluminum interstitials along grain boundaries was believed to be the dominant sintering mechanism, with an estimated activation energy of 488 ± 20 kj/mol for conventional sintering and an average activation energy of 468 ± 20 kj/mol for plasma sintering. A comparison of specimens sintered in the plasma to those sintered in a conventional furnace under the same temperature-time excursions and oxygen pressures showed an athermal effect due to the plasma. To further explore this athermal effect, sintering experiments in plasmas of different oxygen pressure were conducted. The athermal effect was ascribed to an increase of aluminum interstitial concentration during plasma sintering. Sintering data were interpreted using the combined-stage sintering model.