摘要
以钙质铬酸镧微粉为主原料,研究了分别添加ZrO2、CaO、MgO、SiO2或Al2O3五种微粉对铬酸镧材料烧结的影响。通过测定试样的体积密度、显气孔率,并借助电镜观察分析,对铬酸镧材料的烧结性进行了探讨。结果表明:在铬酸镧材料中分别添加ZrO2、CaO、MgO、SiO2或Al2O3,均能促进材料的烧结,使材料达到致密,并能使烧结温度降到1650℃。从显微结构看,添加ZrO2、MgO或CaO的铬酸镧烧结体,晶粒以固-固结合为主,而添加SiO2或Al2O3的铬酸镧烧结体晶粒间则以液相结合为主,且结构中有较多的封闭气孔。当温度再升高时,由于铬离子的挥发以及具有较低体积密度的相的生成,反而会使铬酸镧材料的密度下降。
Influences of five micropowder additives （ZrO2, CaO, MgO, SiO2 and Al2O3 ） on sintering of lanthanum chromate with calcium based lanthanum chromate micropowder as main raw material were discussed. The sintering properties were analyzed by examining bulk density and apparent porosity,and SEM. The results show that：Adding ZrO2,CaO, MgO, SiO2 or Al2O3 seperately can all accelerate the sintering of the specimens,make them densification,and lower the sintering temperature to 1650℃ ;The bonding among grains of LaCrO3 with ZrO2, MgO or CaO mainly is solid -solid bonding ,while that with SiO2 or Al2O3 mainly is liquid bonding, and there are many closed pores in the structure; If the temperature is higher, density of LaCrO3 materials will decrease due to the volatilization of chromium cation and the formation of phase with lower bulk density.
出处
《耐火材料》
EI
CAS
北大核心
2007年第6期439-442,共4页
Refractories
