Phase Reconstruction and Microstructure Evolution of Magnesia-carbon Refractories at High Temperatures in Nitrogen  

作　　者：YAN Mingwei YANG Yumin TONG Shanghao ZHANG Jiayu SUN Guangchao LIU Kaiqi 

机构地区：[1]State Key Laboratory of Multiphase Complex Systems,Institute of Process Engineering,Chinese Academy of Sciences,Beijing 100190,China [2]Nanjing IPE Institute of Green Manufacturing Industry,Nanjing 211135,China [3]AVIC Tianshui New&High Abrasives Co.,Ltd.,Tianshui 741024,China [4]Luoyang Lirr Functional Materials Co.,Ltd.,Luoyang 471039,China

出　　处：《China's Refractories》2022年第3期14-23,共10页中国耐火材料（英文版）

摘　　要：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 1300-1600℃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 1300-1500℃,the non-oxides within the specimens are aluminum carbide(Al_(4)C_(3)),aluminum nitride(AlN)and magnesium aluminum nitride(Mg_(3)Al_(n)N_(n+2),n=2 or 3);at 1600℃,the diffraction characteristic peak intensity of Al_(4)C_(3) and AlN decreases sharply,and sharp diffraction characteristic peaks of nitrogen aluminum carbide(Al_(7)C_(3)N_(3))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 O_(2)(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.

关 键 词：magnesia-carbon refractory phase reconstruction MICROSTRUCTURE non-oxide MAGNESIA 

分 类 号：TQ175.1[化学工程—硅酸盐工业]