Microwave Heating Sintering R-lialo <sub> 2 </ Sub> Ceramics Technology Research

Lithium aluminate is of excellent physical and chemical properties. Soγ?LiAlO2 have good prospects in the three areas,such as the substrate material for GaN epitaxial growth; the matrix material of molten carbonate fuel cell;the deuterium solid value-added material of fusion reactor side. Therefore, the researchers are pay attention to the preparation technology ofγ?LiAlO2. And theγ?LiAlO2's preparation of shapes mostly focus on powder, single crystal, substrate, while the preparation ofγ?LiAlO2 ceramic is few. Not to mention using the microwave sintering method sythesizedγ?LiAlO2ceramics. But Jiang Zuozhong, in Tsinghua University, fingered out using the microwave sintering method sythesizedγ?LiAlO2ceramics is feasible.In this paper, using Li 2CO3 purity of 99.99% and Al 2O3 purity of 98.9% as the raw material, and using the microwave sintering method synthesizedγ?LiAlO2 ceramics. The main task of this paper is to use different sintering programs sinter samples, enventually sinter single-phaseγ?LiAlO2 ceramics with high density and sum up the best preparation technology of microwave sintering r ? LiAlO2ceramics. On the analysis of the microwave power,time and sintering temperature during the sintering process,we found that, adding a layer of Al 2O3 powder between the mold and samples can help to promote the samples of the microwave absorption, which is different from traditional internal mixing in the samples. It is a new method which contribute to samples absorbing microwave. Through the X-ray diffraction test and analysis of the samples, which were sintered under different sintering conditions, summarized the best preparation technology using microwave sintering r ? LiAlO2 ceramic. That is, the maximum sintering temperature range is 1362-1450℃, and holding time is 60min. At the same time, at the highest sintering temperature of 1450℃and holding time of 60min , the single-phase r ? LiAlO2 ceramics were synthesized with its density reached 98%. By observing SEM graphs of r ? LiAlO2 ceramics, which is sintered at the highest sintering temperature of 1362℃, the result indicate, the local grain size is identical with about 0.625um ,and the shape of grain is needle.