陈昌平，高景霞，杨会智，孙洪魏，胡 行
(郑州大学，材料物理教育部重点实验室，郑州 450052)
摘 要：通过常见添加剂MgO, Y2O3, TiO2, MnO2 及CAS(CaO–Al2O3–SiO2玻璃)等对纳米α–Al2O3助烧性能的比较，选出以TiO2，CAS及MnO2为代表的三元添加剂进行单纯形格子设计及回归分析。结果表明：复合添加剂TiO2–CAS–MnO2的比例对样品致密化及显微结构有着显著的影响。TiO2，CAS及MnO2按一定比例引入到纳米α–Al2O3可实现最大致密化速率，却易引起晶体的异常长大和异向生长；而仅CAS与MnO2按一定比例引入比单一添加CAS或MnO2更能促进纳米α–Al2O3的烧结，样品平均晶粒尺寸约为3μm，且分布均匀，几乎无晶粒异常生长现象。
关键词：纳米氧化铝；复合添加剂；致密化；单纯形设计
EFFECTS OF COMPOSITE ADDITIVES ON DENSIFICATION
OF NANO ALUMINA CERAMICS
CHEN Changping，GAO Jingxia，YANG Huizi，SUN Hongwei，HU Xing
(Material Physics Laboratory of Ministry of Education, Zhengzhou University, Zhengzhou 450052, China)
Abstract: By comparing the effect of several classical additives MgO, Y2O3, TiO2, MnO2 and CAS (CaO–Al2O3–SiO2 glass) on the sintering behavior of nanoα–Al2O3. The TiO2, CAS and MnO2 were selected to act as a ternary composite additive to study their effects using simplex designs as well as regression analysis. The experimental results show that TiO2–CAS–MnO2 has important influence on the densification and microstructure of samples. A certain ratio of TiO2, CAS and MnO2 can achieve a fast densification rate,while causing abnormal and anisotropic grain growth. Co-doping only with MnO2 and CAS can improve the sintering behavior of the samples and results in a more uniform distribution of matrix grains with an average size of 3 μm and almost completely without abnormal grain growth.
Key words: nano-alumina; composite additives; densification; simplex design
近些年来，随着纳米科技的进步和纳米粉体制备技术的迅速发展，利用纳米α–Al2O3粉体为原料制备Al2O3陶瓷及其复合材料等得到了广泛的应用，它为降低陶瓷材料的烧结温度，改善制品的微观结构，提高材料的力学性能(如：硬度、强度、韧性以及耐磨性等)开辟了一条新的途径[1]。然而，由于纳米粉体颗粒的表面能较大，高温烧结的过程中晶粒生长迅速，因而几乎所有关于这方面的研究中最重要的问题都是在致密化的过程中如何抑制晶粒的生长及其异常长大[2]。为此，材料学界从烧结动力学观点出发采取了多种方式对此加以控制，如：引入添加剂、两步烧结、超高压成型、热压、热等静压、微波烧结及等离子体烧结等[3]。在以上方法中，以原料中引入一定量的添加剂具有操作简单，成本低廉及生产效率高等诸多优点而成为当前人们研究的重点[4]。
一般而言，少量添加剂即可对Al2O3陶瓷的致密化及其显微结构产生一定的影响，尤其是以一定比例复合形式引入时效果更加明显[5]'">............
