MgO-MgAl2O4-ZrO2分系亚固线温度相关系  

Phase relationship at subsolidus temperature of MgO-MgAl2O4-ZrO2 subsystem

作　　者：高振昕[1,2] Gao Zhenxin(Sinosteel Luoyang Institute of Refractories Research Co.,Ltd.,Luoyang 471039,Henan,China)

机构地区：[1]中钢集团洛阳耐火材料研究院有限公司 [2]濮阳濮耐高温材料(集团)股份有限公司北京研发中心

出　　处：《耐火材料》2019年第4期241-246,共6页Refractories

摘　　要：以分析纯的MgO粉、Al2O3粉和ZrO2粉为原料制备了ZrO2含量(w)分别为20%、30%和40%的3组φ10 mm×10 mm的圆柱样,分别经1 600℃保温5 h、1 700℃保温0和1 800℃保温7 h烧结后,借助于场发射扫描电镜研究了MgO-MgAl2O4-ZrO2分系组成的显微结构。结果表明:1)在1 600~1 700℃温度范围内,MgO-MgAl2O4-ZrO2分系材料为固相反应,呈方镁石、尖晶石和ZrO 2(固溶Mg^2+)三相共存,尖晶石化影响致密程度;2)ZrO 2为40%(w)的试样经1 800℃烧后,为非均态熔融的显微结构,部分区域可形成典型的MgO+MgAl 2O 4+ZrO 2三元共晶,其组成(w)为:MgO 35.2%~37.2%,Al2O3 24.2%~26.6%,ZrO2 37.2%~39.8%。Three groups of cylinder specimens (φ10 mm×10 mm) with 20%,30% and 40%(by mass,the same hereinafter) of ZrO2,were prepared using analytically pure MgO,Al2O3 and ZrO2 powder as starting materials.The specimens were fired at 1 600 ℃ for 5 h,1 700 ℃ for 0 h and 1 800 ℃ for 7 h,respectively.The microstructure of the MgO-MgAl2O4 - ZrO2 subsystem was studied by FESEM.The results show that (1)in the temperature range of 1 600-1 700 ℃,solid reactions happen in the MgO-MgAl2O4-ZrO2 subsystem,leaving three phases:periclase,spinel and ZrO2 (solid dissolving with Mg^2+) co-existing;spinellization affects the densification;(2)the specimen with 40% ZrO2 fired at 1 800 ℃ has heterogeneous melting microstructure;some areas form typical ternary eutectic MgO-MgAl2O4 - ZrO2 with composition of MgO 35.2%-37.2%,Al2O3 24.2%-26.6%,and ZrO2 37.2%-39.8%.

关 键 词：MgO-MgAl2O4-ZrO2分系 亚固线 相关系 显微结构 

分 类 号：TQ175[化学工程—硅酸盐工业]