Nb,Mo,Ti,Ta,W掺杂硅化石墨扫描电镜研究  

STUDY ON SCANNING ELECTRON MICROSCOPE OF Nb,Mo,Ti,Ta,W DOPING SILICATED GRAPHITE

作　　者：葛学贵[1] 曹宏[1] 黄少云[2] 陈亦凡[1] 靳化才[1] 杨蜜纯[1] 

机构地区：[1]中国地质大学材料科学与化学工程学院,湖北武汉430074 [2]武汉化工学院,湖北武汉430073

出　　处：《地质科技情报》2001年第4期77-82,共6页Geological Science and Technology Information

基　　金：国家自然科学基金资助项目 ( 4 9872 0 2 1);中国地质大学岩石矿物应用开发实验室基金资助项目

摘　　要：以硅粉的 1% ,2 %～ 10 % ( w B)将 Nb,Mo,Ti,Ta,W等 5种金属粉掺入硅粉中 ,用液硅渗透法 ( LSP)制备出系列掺杂硅化石墨样品。对这些样品抗折、抗拉强度测试结果表明 :Nb( 6 % ) -硅化石墨性能最优 ,抗拉强度提高了 2 0 %～ 2 7% ;Mo( 1% )、Mo( 5 % )掺杂效果次之 ;而 Ti( 7% )、Ta( 3% )、W( 7% )等的掺杂反使材料强度降低。扫描电子显微镜 ( SEM)分析显示 :Nb( 6 % )掺杂使抗拉强度增强的原因在于 ,新的铌与碳的间隙化合物相的生成 ,减小了硅化石墨显微结构的尺寸 ,且使材料外层及内核结构均匀、致密、统一 ,因而能有效分散应力集中 ,缓冲裂纹扩张 ,增大承载截面 ,从而提高材料力学性能。相反 Ti( 7% )、Ta( 3% )等掺杂后 ,尽管使材料外层结构致密 ,但内部结构疏松 ,晶粒、孔隙尺寸大小不一 ,形态各异 ,内、外结构极不统一 。When 1%,2%-10%silicon powdering and five metals of Nb,Mo,Ti,Ta,W were added to silicon powder,a series of doping silicated graphite sample were prepared by LSP.The result of anti bending and anti tensile strength test of samples showed:Nb(6%) silicated graphite property is the best of all,with its tensile strength increasing 20%-27%;effect of doping of Mo(1%),Mo(5%) takes the second place.But doping of Ti(7%),Ta(3%) and W(7%),in contrast,seems reduce the material intension.The analysis of SEM shows that Nb(6%) doping enhancement is attributed to the formation of the new clearance compound phase of Nb and C.This formation diminishes the silicated graphite microstructure size,which leads to the uniformity and compactedness of the outer layer and kernel structures.This can effectively disperse stress concentration,buffer creackle expandsion,increase bear ability of the weight of section and accordingly enhance material mechanics property.In the opposition,Ti (7%),Ta(3%) and other doping silicated graphite leads material outer layer structure to compactedness,but inner structure to looseness,different crystal and hole size,configuration diversifying,and inner and outer structure to disunity.Hence,it destroys material property.

关 键 词：掺杂 硅化石墨 扫描电子显微镜 镍 钛 钨 抗拉强度 

分 类 号：TQ165[化学工程—高温制品工业]