SiC基陶瓷高温相平衡——SiC-Si_3N_4-Gd_2O_3系统  

High Temperature Phase Equlibrium of Silicon Carbide Based Ceramics——Phase Relations of SiC-Si_3N_4-Gd_2O_3 System

作　　者：孙文周[1] 陈宇红[1] 黄振坤[1] 吴澜尔[1] 江涌[1] 

机构地区：[1]北方民族大学材料科学与工程学院,银川750021

出　　处：《硅酸盐学报》2011年第10期1536-1540,共5页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金(NSFC50962001)资助项目

摘　　要：通过热压烧结在1700℃,分别于Ar和N2气氛下制备了一系列SiC-Si3N4-Gd2O3陶瓷样品,采用X射线衍射技术分析了样品的相组成,确定了相关系。结果表明:在SiC-Si3N4-Gd2O3的二元子系统和三元系统中,除了二元化合物Si3N4.Gd2O3(M相)存在,尚有含氮稀土硅酸盐化合物Si2N2O 2Gd2O3(J相)和Gd10(SiO4)6N2(H相)生成。而这些化合物的生成主要是由于SiC、Si3N4粉料表面的杂质氧(以SiO2形式存在)参与了反应,由此引入的SiO2这一组分,使原三元系统扩大成为SiC-Si3N4-SiO2-Gd2O3四元系统。通过对产物相组成的分析,确定了在此四元系统中存在8个相容性四面体。基于上述结果,提出了1 700℃的SiC-Si3N4-Gd2O3准三元亚固相图、Si3N4-Gd2O3-SiO2三元亚固相图以及SiC-Si3N4-SiO2-Gd2O3四元亚固相图。The samples of SiC-Si3N4-Gd203 system were prepared by a hot pressure sintering （HP） method in N2 and Ar atmospheres at 1 700 ℃. The phase compositions of the samples were analyzed by X-ray diffraction to determine the phase relations. The results show that, except for Si3N4-Gd203 （M phase）, two oxygen-rich rare-earth siliconoxynitrides Si2N20＂2Gd203 （J phase） and Gdlo（SiO4）6N2 （H phase）, are also formed in the ternary system and binary subsystems SiC-Si3Na-3d203 due to the presence of excess oxygen impurity in the starting powders of SiC and Si3N4. The ternary system was transformed into a quaternary system due to the introduction of SiO2. In the system, eight compatible tetrahedrons were determined. The subsolidus phase diagrams at 1 700 ℃ for the trinary SiC-Si3N4-GdzO3 system, Si3N4-d203-SiO2 system and the quaternary SiC-Si3N4-SiO2-Gd203 system could be proposed based on the results obtained.

关 键 词：碳化硅 氮化硅 氧化钆 相平衡:相图 

分 类 号：TQ170.1[化学工程—硅酸盐工业]