作者：YAN Mingwei1,2YANG Yumin3TONG Shanghao4ZHANG Jiayu1SUN Guangchao1,2LIU Kaiqi1,2

作者单位：1. State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences2. Nanjing IPE Institute of Green Manufacturing Industry 3. AVIC Tianshui New & High Abrasives Co., Ltd. 4. Luoyang Lirr Functional Materials Co., Ltd.

刊名：China’s Refractories

ISSN：1004-4493

出版年：2022-09-15

卷：31

期：3

起页：14-23

止页：

分类号：TQ175.1

语种：英文

关键词：

内容简介

Magnesia-carbon refractories were prepared using fused magnesia, flake graphite and metal aluminum powder as starting materials, phenolic resin as the binder, heat-treating at 1 300-1 600 ℃ in nitrogen atmosphere. The phase reconstruction and the microstructure evolution of the obtained magnesia-carbon refractories were analyzed. The formation mechanisms of magnesia crystals with different morphologies by chemical vapor deposition were revealed. The results show that at 1 300-1 500 ℃, the non-oxides within the specimens are aluminum carbide(Al4C3), aluminum nitride(AlN) and magnesium aluminum nitride(Mg3AlnNn+2, n=2 or 3); at 1 600 ℃, the diffraction characteristic peak intensity of Al4C3 and AlN decreases sharply, and sharp diffraction characteristic peaks of nitrogen aluminum carbide(Al7C3N3) appear. Mg(g) is produced by the aluminothermic reduction and carbothermal reduction of magnesia. On the surface of the specimens, Mg(g) reacts with oxygen to form MgO whiskers. Inside the specimens, Mg(g) and O2(g) undergo a CVD chemical deposition reaction to form cubic MgO crystals. There is a phase relationship between flake AlN and flake Mg3AlnNn+2, and they are so associated with each other that the morphology is difficult to distinguish.