氮化硅(Si_3N_4)-稀土氧化物陶瓷的超高压烧结研究  

STUDY OF PHASE COMPOSITION OF A SILICON NITRIDE(Si_3N_4)-RARE-EARTH OXIDE CERAMIC SINTERED UNDER HIGH PRESSURES

作　　者：沈中毅[1] 孙继荣[1] 刘世超[1] 刘勇[1] 黄振坤[2] 孙维莹[2] 

机构地区：[1]中国科学院物理研究所,北京100080 [2]中国科学院上海硅酸盐研究所,上海200050

出　　处：《高压物理学报》1993年第1期1-10,共10页Chinese Journal of High Pressure Physics

基　　金：中国科学院上海硅酸盐研究所高性能陶瓷和超微结构开放实验室资助项目

摘　　要：在5～7GPa,600～1800℃的压力-温度范围内对组份为氮化硅-稀土氧化物微粉混合体(3Si_3N,+0.5La_2O_3+0.5Pr_6O_(11)(mol.％))的烧结产物进行了研究。所得结果表明其成相规律与Sialon体系在高温高压下烧结时不同。在直到5GPa的高压力下,α-Si_3N_4表现出相当高的稳定性,并不转变成β相。当烧结温度低于1600℃时,烧结体仍然由以α-Si_3N_4为基础的固溶体及稀土氧化物组成,而后者则表现出一系列相变化。当压力超过6GPa、温度高于1600℃时,物料烧结成一个新的单相高压结构ReSi_3O_2N_4。其衍射数据可以用一个正交点阵来拟合。其晶格参数为:α=1.2983nm,b=0.8140nm,c=0.4285nm。The phase compositions of silicon nitride-rare-earth oxide ceramic (3Si3N4 +0.5La2O3+0. 5Pr6O11(mol. %) sintered in a pressure range from 5 to 7GPa, temperature from 600℃ to 1800℃ has been studied by X-ray diffraction and SEM observation. The observed results show that the phase forming rule at high p-T is different from that of Si3N4-Al2O3-AlN system. Under high pressure and below 1600℃ ,the sintering products are mixture of Si3N4 and the polymorphs of the rare-earth oxides. Si3N4 remains α-structure even when certain amount of rare-earth oxides has dissolved in. When the temperature exceeds 1600℃ and pressure is above 6GPa, a new single phase belonging to orthorhombic system is formed with lattice parameters a =1. 2983nm,6=0. 8140nm,c=0. 4285nm.

关 键 词：烧结 氮化硅陶瓷 稀土族 氧化物 

分 类 号：TQ174.651[化学工程—陶瓷工业]