摘要
以粒度为3～4μm的苏州土、8～10μm的滑石粉和2—3μm的工业氧化铝为原料，在MgO—Al2O3-SiO2三元相图低膨胀区选取不同的组成点配料，困料3d以上，以4．7MPa压力半干压法成型为10mm×10mm×53mm的试样，60℃干燥24h后入炉于1400℃烧成。试验中设计了直接升温法和两种成核一生长法烧成制度，测试了这3种烧成制度下烧成试样的热膨胀系数，并采用扫描电镜和X射线衍射分析显微结构和物相组成。结果表明：采用烧成制度Ⅲ的成核一生长法，最佳烧成温度为1400℃时，可获得热膨胀系数为（1．6—1．7）×10^-6℃^-1的堇青石材料；而且对促进晶核发育，降低合成堇青石材料热膨胀系数确实有利。
Specimens were prepared by selecting composition points in low thermal expansion areas of ternary phase diagram of MgO-Al2O3-SiO2 ,using Suzhou clay （3-4 μm）,talcum powder （8-10 μm）,and industrial alumina （2-3μm） as starting materials,aging for more than 3 days,pressing into the bars with the size of 10 mm × 10 mm ×53 mm by semi-dry method under 4. 7 MPa,drying at 60 ℃ for24 h,and then firing at 1400 ℃. Direct-heating up and two nucleation-growth schedules were designed. The thermal expansion coefficients of the fired specimens were tested. Microstructure and phase composition were analyzed by SEM and XRD. The results show that the cordierite with thermal expansion coefficient of （1.6-1. 7） × 10^-6 ℃^-1 can be obtained by firing at 1 400 ℃ with schedule 111 ,nucleation-growth method,and that is truly benefit to boost nuclear growth and reduce the thermal expansion coefficient.
出处
《耐火材料》
CAS
北大核心
2011年第4期285-287,共3页
Refractories
关键词
堇青石
热膨胀系数
烧成曲线
Cordierite,Thermal expansion coefficient,Firing schedule
