烧成温度对氧化铝微球改性龙泉青瓷物理性能影响研究

Effect of Sintering Temperature on Physical Properties of Longquan Celadon Modified with Alumina Microspheres

氧化铝微球具有堆积密度大、体积比容量高、流动性好、烧结活性高等特点,可用于陶瓷材料的增强改性。采用扫描电镜(SEM)、热重-差示扫描仪(TG-DSC)、X-射线衍射仪(XRD)、三点弯曲仪等测试技术研究了不同烧成温度(1250℃-1370℃)下氧化铝微球改性龙泉青瓷样品的收缩率、吸水率、密度、物相组成、抗弯强度等特性,并探究了其微观结构及增强改性机制。结果表明,水热法合成的刚玉相氧化铝粉体呈微球型,粒径约250μm;随着烧成温度增加,氧化铝微球改性龙泉青瓷样品抗弯强度、收缩率与密度逐渐提升,而当烧成温度达到1370℃后,陶瓷性能呈现下降;当氧化铝微球含量为20%、烧成温度为1340℃、烧成时间为10h时所制备的样品拥有最佳的物理性能,其抗弯强度为79.16 MPa,总收缩率为10.63%,吸水率为0.064%,密度为2.38 g·cm^(-3),其主要归因于长柱状晶粒的形成及均匀分布。

With the characteristics of high bulk density,high volume specific capacity,good fluidity and high sintering activity,alumina microspheres can be utilized for reinforcement and modification of ceramic materials.The effects of sintering temperature(1250-1370℃)on bending strength,linear shrinkage,water absorption and density of the alumina microsphere-modified Longquan celadon were studied,while the mechanism of the microstructural variation was proposed.Scanning electron microscopy(SEM),thermogravimetry-differential scanning calorimeter(TG-DSC),X-ray diffraction(XRD)and three-point bending test were employed to characterize microstructure,phase composition and bending strength of the samples.Microspherical corundum Al_(2)O_(3) powder with an average size of 250μm was achieved.With increasing sintering temperature,bending strength,linear shrinkage and density of the alumina microsphere-modified Longquan celadon samples were increased first and then decreased as the sintering temperature reache d to 1370℃.The sample with 20%alumina microsphere after sintering at 1340℃for 10 h showed optimal physical properties,with bending strength of 79.16 MPa,total shrinkage of 10.63%,water absorption was 0.064%,and density of 2.38 g·cm^(-3),which can be attributed to the formation and uniform distribution of long columnar crystalline grains in the celadon.