自增韧氧化铝陶瓷的制备与力学性能研究  

Preparation and Mechanical Properties of Self-Toughening Alumina Ceramics

作　　者：王刚[1] 娄海琴[1] 周继伟[1] 周军[1] 杨彬[1] 

机构地区：[1]中钢集团洛阳耐火材料研究院,河南洛阳471039

出　　处：《稀有金属材料与工程》2008年第A01期512-514,共3页Rare Metal Materials and Engineering

摘　　要：研究了添加La_2O_3、La_2O_3+MgO、La_2O_3+SiO_2、La_2O_3+MgO+SiO_2等复合添加剂对氧化铝陶瓷结构及性能的影响。结果表明,通过改变La_2O_3复合的添加剂种类,可以得到不同显微结构和力学性能的氧化铝陶瓷。添加La_2O_3、La_2O_3+MgO的氧化铝陶瓷晶粒细小,提高了材料的致密度和抗弯强度,但韧性增加不明显;添加La_2O_3+SiO_2的氧化铝陶瓷,晶粒有异常长大现象,微结构不均匀,导致力学性能降低;而添加La_2O_3+MgO+SiO_2复合添加的氧化铝陶瓷,获得了具有一定长径比、结构较均匀的自增韧结构氧化铝陶瓷,其抗弯强度和断裂韧性分别达到459 MPa和4.6MPa.m^(1/2)。The effects of La2O3, SiO2, MgO additives on the mechanical properties and microstructures of alumina ceramics were investgated. Introducing a second component into La2O3 resulted in different microstructures and mechanical properties of the alumina ceramics. The ceramics from the La2O3 and La2O3＋MgO consisted of fine grains, have a higher density and bending strength but showed negligible improvement in toughness. Introducing SiO2 into La2O3 contribited only a little to the densification of alumina. In this case, anisotropic growth of some alumina grains occurred to form inhomogenous microstructures and reduced the mechanical properties of the ceramics. Differently, sintering using the La2O3＋MgO＋SiO2 additives yielded highly dense ceramics consisting of uniform rod-like grains of certain aspect ratio. The bending strength and fracture toughness of the ceramics attained 459 MPa and 4.6 MPa·m^1/2 respectively.

关 键 词：氧化铝 自增韧 显微结构 力学性能 

分 类 号：TQ174.1[化学工程—陶瓷工业]