纳米Fe包覆Si3N4的制备及其高温烧结微观组织  

Preparation and sintering microstructure of nanometer Fe coated Si_3N_4 composite powders

作　　者：银锐明[1,2] 范景莲[1] 黄伯云[1] 刘勋[1] 

机构地区：[1]中南大学粉末冶金国家重点实验室,长沙410083 [2]湖南工业大学包装与材料工程学院,株洲412008

出　　处：《复合材料学报》2009年第2期30-36,共7页Acta Materiae Compositae Sinica

基　　金：国家自然科学基金创新研究群体科学基金(50721003);国家自然科学基金(50804016)

摘　　要：采用非均相沉淀-热还原法制备了Fe/Si3N4颗粒复合粉末并在热处理温度1873 K和0.1 MPa氮气气氛下进行常压与热压烧结。通过扫描电镜(SEM)、透射电镜(TEM)、电子能谱(EDS)、X射线衍射(XRD)等方法观察Fe/Si3N4复合粉末的结构形貌及常压、热压烧结后的微观组织。结果表明:Fe/Si3N4复合粉末物相主要存在Fe相与Si3N4相,微观结构为纳米薄层Fe均匀包覆Si3N4颗粒;高温烧结后的常压与热压样品的组织成分与微观结构有极大的不同,除了存在Si3N4相之外,常压样品金属Fe相衍射峰消失,并有晶粒粗大铁硅化合物生成,热压样品则保留有金属Fe相,并存在晶粒相对细小铁硅化合物及致密的玻璃态物质。Fe/Si3N4 composite powder was synthesized by the heterogeneous precipitation-thermal reduction process, and then pressed into flakes under a pressure of 10 MPa. The flakes were sintered by pressureless and hot-pressing at 1873 K in 0.1 MPa N2. The chemical composition, microstructure and phases of the composite powder and the sintered flakes were investigated by scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, energy dispersive spectroscopy （EDS） and X-ray diffraction （XRD）, It is proved that the structure of the composite powders is Sia N4 coated by nano Fe. The crystal phases of sintered flakes by pressureless are iron silicide, SiC and SiaN4. The crystal phases of the sintered samples by hot pressing are Fe, iron silicide and SiaN4. It is found that the crystal phases flakes bv Dressureless and hot-pressing are very different.

关 键 词：包覆 Fe SI3N4 非均相沉淀 热力学 

分 类 号：TB333[一般工业技术—材料科学与工程]