立方氮化硅粉体的超高压烧结特性  

SINTERING CHARACTERISTICS OF CUBIC SILICON NITRIDE POWDER UNDER ULTRAHIGH PRESSURE

作　　者：姚怀[1,2] 唐敬友[1] 唐翠霞[1] 刘雨生[3] 贺红亮[3] 寇自力[4] 贺端威[4] 

机构地区：[1]西南科技大学,极端条件物质特性实验室,四川绵阳621010 [2]河南科技大学材料科学与工程学院,河南洛阳471003 [3]中国工程物理研究院流体物理研究所,冲击波物理与爆轰物理国立重点实验室,四川绵阳621900 [4]四川大学原子与分子物理研究所,成都610065

出　　处：《硅酸盐学报》2008年第2期224-227,共4页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金(50472102);中国工程物理研究院科学技术基金(20050864);西南科技大学引进人才基金(ZK043130)资助项目。

摘　　要：以冲击波合成的立方氮化硅(γ-Si_3N_4)粉体为原料,添加Y_2O_3-Al_2O_3-La_2O_3系烧结助剂,进行了超高压烧结,研究了在不同烧结温度与压力下,烧结样品的相对密度、力学性能、物相变化及显微结构。经5.4～5.7 GPa和1670～1770K,保温保压15 min超高压烧结后,烧结制备的氮化硅陶瓷主要由长柱状晶粒组成,显微结构均匀,γ-Si_3N_4已完全转化为β-Si_3N_4。烧结样品的最高相对密度与Vickers硬度分别为99.16%,23.42GPa。Silicon nitride ceramics were prepared by super-high pressure sintering using cubic silicon nitride powders synthesized by the shock-compression technique as raw materials and with Y2O3-Al2O3-La2O3 mixtures as additives.The relative density,mechanical properties,phase transition and microstructure of sintered compacts under different pressures and temperatures were investigated. Silicon nitride ceramics obtained at pressures of 5.4-5.7 GPa and temperatures of 1 670-1 770 K for 15 min were mainly composed of elongatedβ-Si3N4 rod crystals with disordered orientation and uniform microstructures,and the cubic Si3N4 in raw powder was com- pletely transformed intoβ-Si3N4.The highest relative density and Vickers hardness in the as-sintered samples were 99.16% and 23.42 GPa respectively.

关 键 词：立方氮化硅粉体 力学性能 显微结构 超高压烧结 

分 类 号：O771[理学—晶体学]