冲击波合成立方氮化硅的烧结稳定性研究  

Research on Sintering Stability of Cubic Silicon Nitride Synthesized by Shock-wave

作　　者：姚怀[1] 徐巧玉[2] 齐鑫[3] 唐敬友[4] 刘海洋[1] 苌清华[1] 

机构地区：[1]河南科技大学材料科学与工程学院,洛阳471003 [2]河南科技大学机电工程学院,洛阳471003 [3]哈尔滨理工大学计算机科学与技术学院,哈尔滨150080 [4]西南科技大学材料科学与工程学院,绵阳621010

出　　处：《无机材料学报》2008年第4期819-823,共5页Journal of Inorganic Materials

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)

摘　　要：以冲击波合成的γ-Si_3N_4粉体为原料,Y_2O_3-Al_2O_3-La_2O_3体系作烧结助剂,在5.7GPa、1370～1670K的高温高压条件下,进行了γ-Si_3N_4粉体的烧结.研究了不同烧结温度对γ-Si_3N_4稳定性、相对密度、力学性能及显微结构的影响.结果表明:γ-Si_3N_4在1420～1670K的条件下,完全相变为β-Si_3N_4,在1370K左右的条件下,发生部分向β-Si_3N_4相变.在5.7GPa,1370K的条件下,烧结样品的相对密度与维氏硬度分别为98.83%和21.09GPa.Silicon nitride ceramics was prepared by super-high pressure using the γ-Si3N4 powders synthesized by the shock-wave technique as raw materials and with Y2O3-Al2O3-La2O3 mixtures as additives at 5.7GPa from 1370K to 1670K. The stability, relative density, mechanical properties and microstructure of the compacts synthesized at different temperatures were investigated. The results show that 7-Si3N4 is completely transformed to γ-Si3N4 at temperature from 1420K to 1670K, and partly transforlned to β-Si3N4 at 1370K. Micro-analysis indicates that the typical microstructure of sintered Si3N4 is mainly composed of β-Si3N4 rod crystals with disordered orientation and uniform microstructures. The relative density and Vickers hardness in the as-sintered （5.7GPa, 1370K） samples are 98.83% and 21.09GPa, respectively.

关 键 词：冲击波合成 高温高压 烧结 相变 稳定性 

分 类 号：O771[理学—晶体学]