二元烧结助剂增强氧化铝陶瓷的微观结构及性能

• 作 者: 胡彦君 尹自强 龚雨波 杨治刚 杨占平 梁银春 董德俊 赵晋津
• 出 处: 中南大学学报（英文版）
• 发表日期: 2021年12期
• 关键词: alumina ceramics binary sintering aids mechanical properties microstructure

Al2O3陶瓷广泛应用于刀具、激光冲击材料、路基基板、耐火材料等领域.本文以MgO和SiO2作为烧结助剂,通过低成本无压烧结技术制备了Al2O3陶瓷,并研究了烧结温度和二元烧结助剂配比对Al2O3陶瓷力学性能和显微组织的影响.XRD和EDS分析结果表明,在样品中加入MgO和SiO2后形成了尖晶石相(MgAl2O4).当烧结助剂总量固定、MgO的掺加量为20 wt％、烧结温度为1550°C时,烧结性能最佳.烧结样品的抗弯强度和密度的最大值分别为314 MPa和3.73 g/cm3.适量SiO2的加入有利于液相烧结形成和大孔隙的去除.同时,从样品的微观结构来看,少量MgO的掺入对晶粒细化产生了影响.综上表明,MgO和SiO2是促进氧化铝陶瓷致密化和性能提升的理想烧结助剂.“,”Alumina ceramics are widely used in many fields such as cutting tools, laser shock materials, roadbed board and refractory. Herein, Al2O3 ceramics are prepared by a low-cost pressureless sintering technology, using the binary sintering aids of MgO and SiO2. The effects of sintering temperature and the ratio of binary sintering aids on the mechanical properties and microstructure of Al2O3 ceramics are investigated. A spinel second phase (MgAl2O4) is found out by the analysis of the results of XRD and EDS when MgO and SiO2 are introduced in the samples. The optimum properties are found when MgO content is 20 wt％ based on the total sintering aids and the sintering temperature is 1550 ° C. The bending strength and the bulk density reach a maximum value of 314 MPa and 3.73 g/cm3, respectively. The addition of appropriate amount of SiO2 makes the formation of liquid phase sintering and the removal of large pores. Meanwhile, a small amount of magnesium oxide doping has an effect on the grain refinement from the microstructure of the sample. Therefore, it is believed that MgO and SiO2 are the ideal sintering aids for promoting the densification and property of alumina ceramics.