α-Si_3N_4与γ-Si_3N_4、α-Si_3N_4混合粉体超高压烧结的比较研究  

Compare Research on Ultra-high Pressure Sintering of α-Si_3N_4 with Mixed Powder of γ- Si_3N_4 and α-Si_3N_4

作　　者：姚怀[1] 徐巧玉[2] 苌清华[1] 唐敬友[3] 

机构地区：[1]河南科技大学材料科学与工程学院,河南洛阳471003 [2]河南科技大学机电工程学院,河南洛阳471003 [3]西南科技大学材料科学与工程学院,四川绵阳621010

出　　处：《佛山陶瓷》2008年第12期8-12,共5页Foshan Ceramics

基　　金：国家自然科学基金v(50472102)

摘　　要：以Y2O3-Al2O3-La2O3体系作烧结助剂,在5.4～5.7GPa、1620～1770K的高温高压条件下进行了α-Si3N4与γ-Si3N4、α-Si3N4粉体的烧结研究,并探讨了烧结温度及压力对烧结体性能的影响。实验结果表明:α-Si3N4、γ-Si3N4完全相变为β-Si3N4;在相同的烧结条件下,α-Si3N4比γ-Si3N4、α-Si3N4混合粉体烧结试样的相对密度、维氏硬度高。α-Si3N4与γ-Si3N4、α-Si3N4混合粉体烧结试样的最高相对密度与维氏硬度分别为98.78%、21.87GPa和98.71%、21.76GPa。烧结体由相互交错的长柱状β-Si3N4晶粒组成,显微结构均匀。Ultrahigh pressure sintering of α-Si3N4 and mixtures of α-Si3N4 and Y-Si3N4 with Y2O3-Al2O3-La2O3 as additives were studied under pressure of 5.4-5.7 GPa and temperature of 1570-1770K. The effects of sintering temperatures and pressures on properties of sintered ceramic samples were investigated. The results show that γ-Si3N4 and α-Si3N4 is transformed to β-Si3N4 completely. The relative densities and Vickers hardness （HV） of sintered samples from α-Si3N4 are larger than those from the mixtures of γ-Si3N4 and α-Si3N4 under the same conditions. The highest relative density and Vickers hardness （HV） of the sintered samples are 98.78%.21.87GPa and 98.71% 、21.76GPa to pure α -Si3N4 and mixtures of γ-Si3N4 and α -Si3N4, respectively. The sintered samples were composed of elongated β -Si3N4 rod crystals with disordered orientation and had an uniform microstructure.

关 键 词：超高压烧结 相变 力学性能 显微结构 

分 类 号：TF124.5[冶金工程—粉末冶金]