【摘要】 Si3N4基复合陶瓷材料具有广阔的应用前景,但由于其强共价键,很难烧结致密。本文采用Y2O3-Al2O3复合烧结助剂,制备了Si3N4/TiCnano复合陶瓷材料,并研究了Y2O3和Al2O3的配比、含量对纳米复合陶瓷材料力学性能、致密化进程和烧结性能的影响。研究结果表明两者配比为2∶3、总含量为10Vol.%时,可以获得较高的致密度和较好的烧结性能,此时材料的力学性能最好,其力学性能指标为:抗弯强度938.6MPa,显微硬度16.01GPa,断裂韧性为6.78MPa·m1/2。利用SEM分析发现材料致密度的提高和显微组织的改变是其力学性能提高的根本原因。更多还原

【Abstract】 Si3N4-based composite ceramic materials possess good future for wide applications. It is difficult to get densified material due to its covalent nature of bonding. In this study one kind of Si3N4/TiCnano composite ceramic material was fabricated using Y2O3 and Al2O3 as sintering additives.The mechanical properties, densifica tion process and sintering properties were researched influenced by compound proportion and volume fraction of sintering additives. In this study, the optimal compound proportion of Y2O3 and Al2O3 is 2∶3, the optimal volume fraction is 10Vol.%. The flexural strength, fracture toughness and hardness are 938.6MPa, 6.78MPa×m1/2 and 16.01GPa respectively. By means of SEM we could find that the densification and microstructure took great performance in the mechanical properties of Si3N4-based composite ceramic materials.更多还原