Co_(2)O_(3)对制备CaZrO_(3)性能的影响  

Influence of Co_(2)O_(3) on properties of prepared CaZrO_(3)

作　　者：张汪年[1] 邓宁[1] 许欢 赵亚军 鞠银燕[1] Zhang Wangnian;Deng Ning;Xu Huan;Zhao Yajun;Ju Yinyan(School of Materials Engineering,Jiujiang University,Jiujiang 332005,Jiangxi,China)

机构地区：[1]九江学院材料科学与工程学院,江西九江332005

出　　处：《耐火材料》2021年第3期213-216,共4页Refractories

摘　　要：以分析纯ZrO_(2)和Ca(OH)2为原料,添加Co_(2)O_(3)(加入质量分数分别为0、0.5%、1.0%、1.5%和2%)粉末,经配料、成型、干燥和烧成(1500、1550和1600℃分别保温3 h)后,通过高温固相法制备了CaZrO_(3)试样。结果表明:随Co_(2)O_(3)添加量的增加,制备CaZrO_(3)的体积密度、线收缩率和平均晶粒尺寸均先增大后减小,显气孔率的变化与之相反。Co_(2)O_(3)分解产生的CoO可以与CaO发生无限置换反应,降低CaO与ZrO_(2)的反应活化能,从而促进试样烧结致密性。但Co_(2)O_(3)添加量超过1.5%(w)时,可能由于Co_(2)O_(3)在分解过程产生较多O_(2),同时产生的CoO短时间内不能固溶到CaO晶体中,处在晶界上,阻碍反应物的直接接触,降低了烧结性能。因此,Co_(2)O_(3)的最佳添加量为1.5%(w),此时CaZrO_(3)试样的体积密度为4.25 g·cm^(-3),显气孔率为3.3%,CaZrO_(3)的平均晶粒尺寸为6.13μm。CaZrO_(3)specimens were prepared by the high-temperature solid state method using analytically pure ZrO_(2) and Ca(OH)2 as raw materials,adding different amounts of Co_(2)O_(3)(0,0.5%,1.0%,1.5%and 2%by mass),batching,molding,drying and firing at different temperatures(1500,1550 and 1600℃for 3 h).The results show that as the Co_(2)O_(3)addition increases,the bulk density,the linear shrinkage and the average grain size of the prepared CaZrO_(3)first increase and then decrease,while the apparent porosity changes in the opposite trend.CoO from the decomposition of Co_(2)O_(3)has infinite displacement reaction with CaO,which reduces the activation energy of the reaction between CaO and ZrO_(2),thus promoting the densification of the specimens.However,when the Co_(2)O_(3)addition exceeds 1.5 mass%,more O_(2) is produced during the decomposition of Co_(2)O_(3),and the generated CoO cannot solid-dissolve with CaO crystals in a short time,which hinders the direct contact of reactants in the grain boundaries thus reducing the sintering performance.Therefore,the optimal addition of Co_(2)O_(3)is 1.5 mass%,and in that case,the specimen has 4.25 g·cm^(-3) of bulk density,3.3%of apparent porosity,and 6.13μm of CaZrO_(3)average grain size.

关 键 词：CaZrO_(3) Co_(2)O_(3) 烧结性能 物相组成 晶粒尺寸 

分 类 号：TQ175.75[化学工程—硅酸盐工业]