【摘要】 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。更多还原

【Abstract】 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.更多还原