Abstract

A ceramic was produced from a nanocrystalline magnesium gallate powder synthesized by the gel combustion method, and the thermal diffusivity of the ceramic at high temperatures was experimentally investigated. The phase and chemical composition of the MgGa₂O₄ ceramic powder was studied by X-ray powder diffraction analysis, X-ray fluorescence spectroscopy, and CHNS elemental analysis. The microstructural parameters of the obtained ceramic material were determined by scanning electron microscopy. The average particle size of the MgGa₂O₄ powder was found to be 80 nm. The ceramic produced by sintering the compacted MgGa₂O₄ powder at 1673 K in air had a density of 4670 kg/m³ (88% of the theoretical density). The average size of the crystalline grains of the ceramic after sintering did not exceed 1 μm. The thermal diffusivity of the ceramic based on MgGa₂O₄ in the temperature range 300–1173 K was for the first time studied by the laser flash method. It was found that its thermal conductivity in the studied temperature range decreased from 2.25 to 0.96 W/(m K).

中文翻译：

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镓酸镁基陶瓷的合成及热物理性能

摘要

以凝胶燃烧法合成的没食子酸镁纳米晶粉末为原料制备陶瓷，并实验研究了陶瓷在高温下的热扩散率。通过X射线粉末衍射分析、X射线荧光光谱和CHNS元素分析研究了MgGa ₂ O ₄陶瓷粉末的物相和化学成分。通过扫描电子显微镜测定所得陶瓷材料的显微结构参数。发现MgGa ₂ O ₄粉末的平均粒径为80nm。通过在空气中以 1673 K 的温度烧结压实的 MgGa ₂ O ₄粉末所生产的陶瓷的密度为 4670 kg/m ³（理论密度的 88%）。烧结后陶瓷晶粒的平均尺寸不超过1μm。首次通过激光闪光法研究了基于 MgGa ₂ O ₄的陶瓷在300-1173 K 温度范围内的热扩散率。发现其在研究温度范围内的热导率从 2.25 降至 0.96 W/(m K)。