摘要
本文基于Si_3N_4-Y_2O_3-MgO液相烧结体系,系统研究了MgO含量和颗粒度对材料致密度、物相组成、显微结构以及力学性能的影响效果与作用机制。结果显示,MgO含量的增加,会使得液相组分增多,进而提高材料的致密度,同时促进β-Si_3N_4晶粒的粗化生长;当液相含量相同但MgO颗粒度增大时,材料致密度和β-Si_3N_4晶粒长径比会同时出现降低趋势。这表明,液相组分MgO的颗粒度会直接影响液相的形成与分布,进而对润湿、颗粒重排及传质过程产生作用。当MgO含量与颗粒度分别为4%和0. 1μm时,材料相对密度、断裂韧性和维氏硬度获得最佳值,分别为99. 5%±0. 2%,(6. 9±0. 6) MPa·m^(1/2),(18. 7±0. 1) GPa。
The effects of MgO content and particle size on the density, phase composition, microstructure and mechanical properties of Si 3N 4-Y 2O 3-MgO liquid phase sintering system were investigated systematically in the present work. Results show that the effect of liquid phase could be more important due to the increase of MgO content, thus resulting in enhancing the final density of material and promoting the coarsening growth of β-Si 3N 4 grains. When the liquid phase content was the same but MgO particle size increased, the final density and aspect ratio of β-Si 3N 4 grains simultaneously tended to diminish. It is found that the MgO particle size has significant influence on the formation and distribution of liquid phase, hence affects the wettability, particle rearrangement and mass transfer during liquid phase sintering process. The relative density, fracture toughness and Vickers hardness reached maximum values of 99.5%±0.2%,(6.9±0.6) MPa·m 1/2 and (18.7±0.1) GPa, respectively at a MgO adding level of 4wt% and a particle size of 0.1 μm.
作者
孟凡
林东涛
左飞
于俊杰
郭伟明
林华泰
MENG Fan;LIN Dong-tao;ZUO Fei;YU Jun-jie;GUO Wei-ming;LIN Hua-tay(School of Electromechanical Engineering, Guangdong University of Technology, Guangzhou 510006, China)
出处
《人工晶体学报》
EI
CAS
北大核心
2019年第4期641-645,共5页
Journal of Synthetic Crystals
基金
国家自然科学基金(51802042)
广东省自然科学基金(2017A030310570
2018A030313353)
广东省科技计划(2017A050501033)
关键词
氮化硅
氧化镁
液相烧结
颗粒度
力学性能
silicon nitride
magnesium oxide
liquid-phase sintering
particle size
mechanical property
作者简介
孟凡(1993-),男,山西省人,硕士研究生。E-mail:15521175179@163.com;通讯作者:左飞,博士,副教授。E-mail:zuofei@gdut.edu.cn.
