低Cr_2O_3含量Al_2O_3-MgO浇注料物理性能及物相变化研究

Study on Physical Properties and Phase Difference of Al_2O_3-MgO Castables with Low Cr_2O_3 Addition

本文研究了低Cr2O3含量Al2O3-MgO浇注料的物理性能,采用X射线衍射仪和扫描电子显微镜对浇注料的物相变化和显微结构进行了分析。结果发现:镁铝尖晶石含量可控制浇注料的显气孔率、体积密度、线变化率及强度。高温下Cr2O3消失是因为其固溶于新生成的MgAl2O4相中,固溶的存在提高了浇注料的物理性能。采用硅微粉结合时,高温下会产生一定的镁橄榄石相。

The physical properties of Al2O3-MgO castables with low Cr2O3 addition were investigated.The microstructure and phase evolution of castables were analyzed using X-ray diffraction（XRD） and scanning electron microscope（SEM）.The results show that the content of MgAl2O4 spinels can determine the apparent porosity,bulk density,line change and strength of Al2O3-MgO castables with low Cr2O3 addition.The phase of Cr2O3 is disappearing in high temperature because low Cr2O3 addition can enter into the new formed MgAl2O4 spinels.That gives rise to lattice activation and improve the performance of the castables.SiO2 ultrfine powder as the binder can result in the existence of Mg2SiO4 phase.