Thermal decomposition characteristics of boehmite gels under microwave heating and associated microstructural features
Thermal decomposition characteristics of boehmite gels under microwave heating and associated microstructural features
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DOI：
10.1016/s0167-577x(97)00228-0
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发表时间：
1998-04
影响因子：
3
通讯作者：
S. Ananthakumar;G. Krishnapriya;A. D. Damodaran;K. Warrier
中科院分区：
文献类型：
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作者：
S. Ananthakumar;G. Krishnapriya;A. D. Damodaran;K. Warrier
介绍了微波脱羟基勃姆石烧结氧化铝的高温致密化及其显微结构特征。在2.45GHz、600 W微波辐照下，勃姆石凝胶在60 min内发生了一系列氧化铝相的转变。通过XRD分析确定了相的形成。微波脱羟基凝胶前驱体在1400°C烧结时的密度为理论密度的95%，平均晶粒尺寸为2 μm。另一方面，部分相同的凝胶前体常规地脱羟基并在1400°C下烧结，得到<90% of density. The boehmite gel heated directly under microwaves reached >97%的理论密度，具有非常精细的微观结构。因此，本研究表明，使用低功率微波脱羟基勃姆石前体凝胶的活性相，进一步可以在常规加热下烧结致密，细粒度的氧化铝的可能性。
High temperature densification and associated microstructural features of alumina derived through sintering of microwave dehydroxylated boehmite are presented. α-alumina has been obtained through a series of transitional alumina phases within 60 min of exposure of boehmite gel to microwaves of 2.45 GHz and 600 W power. The phase formation has been identified by XRD. The surface area measurements on various gel samples exposed to microwaves at intermediate time intervals are also reported.The densification characteristics of microwave dehydroxylated gel precursors when sintered by conventional route resulted 95% of theoretical density at 1400°C and an average grain size of 2 μm. On the other hand, part of the same gel precursor conventionally dehydroxylated and sintered at 1400°C resulted <90% of density. The boehmite gel heated directly under microwaves reached >97% theoretical density with very fine microstructure. Thus, the present study indicates the possibility of using low power microwaves for dehydroxylation of boehmite precursor gels to active phases which further can be sintered under conventional heating to dense, fine grained alumina.