Fe2(Mo04)3/Si3N4复合粉末还原及热压微观组织结构分析

摘要

以α-Si3N4,Fe(NO3)3·9H2O和NH4Mo7O24·4H2O为原料,采用非均相沉淀法制备Fe2(M0O4)3/Si3N4复合粉末,采用氢气还原与热压法获得Fe-Mo/Si3N4复合粉末与烧结体,采用x线衍射仪(XRD)、电子能谱(EDS)、电镜扫描(SEM)和电镜透射(TEM)等方法对Fe-Mo/Si3N4复合粉末与烧结体物相、成分及微结构进行观察与分析.分析结果表明:Fe-Mo/Si3N4复合粉末主要成分为α-Si3N4,Mo,Si和Fe-Mo氮化物(Fe6M07N2和Fe3M03N),其中Mo颗粒长大;粒径为4-7 μm的Mo5Si3大颗粒均匀镶嵌在Si3N4,Fe-Mo氮化物(Fe6Mo7N2和Fe3Mo3N)及Si02的混合物组成的粒径为1 μm左右的小颗粒之中.%Fe2(MoO4)3/Si3N4 was prepared by heterogeneous precipitation-thermal reduction method using α-Si3N4,Fe(NO3)3.9H20 and NH4Mo7O244H20 as raw material, then through reducing by hydrogen and hot pressed, Fe-Mo/Si3N4 composite powder and its sintering body were obtained. Their phases, composition and microstructure were observed and analyzed by XRD, EDS, SEM and TEM. The results show that the Fe-Mo/Si3N4 composite powder consists ofα-Si3N4,Mo, Si and Fe-Mo nitride(Fe6Mo7N2, Fe3Mo3N), in which Mo particle grows, while large Mo particles with size of 4-7 μm are embedded into those small particles composed of Si3N4 and Fe-Mo nitride (Fe6Mo7N2 and Fe3Mo3N) and SiO2 in the microcosmic fracture of Fe-Mo/Si3N4 cermet.