论文部分内容阅读
采用干压成型工艺和气压烧结方法制备了多孔氮化硅陶瓷。研究了烧结温度和保温时间对多孔氮化硅陶瓷显微结构和力学性能的影响,测定了不同烧结制度下多孔氮化硅陶瓷的气孔率、物相组成、弯曲强度和弹性模量,分析了多孔氮化硅陶瓷的微观结构。结果表明:烧结温度的提高可以促进材料的致密化、α→β-Si_3N_4相转变和β-Si_3N_4晶粒的生长,提高材料的弯曲强度。在1 900℃烧结温度条件下,保温15 min获得的多孔氮化硅陶瓷的弯曲强度达到106 MPa,同时保留了较高的气孔率49%。
Porous silicon nitride ceramics were prepared by dry pressing and pressure sintering. The effects of sintering temperature and holding time on the microstructure and mechanical properties of porous Si3N4 ceramics were investigated. The porosity, phase composition, flexural strength and elastic modulus of porous Si3N4 ceramics were measured under different sintering conditions. Microstructure of Porous Silicon Nitride Ceramics. The results show that the sintering temperature can promote the densification, α → β-Si_3N_4 phase transformation and β-Si_3N_4 grain growth, and improve the bending strength of the material. The flexural strength of porous Si3N4 ceramics obtained at the temperature of 1 900 ℃ for 15 min reached 106 MPa, while retaining a high porosity of 49%.