氮气气氛下MgAl_2O_4/SiC材料的反应性能研究  

Reactivity of MgAl_2O_4/SiC Composites in Nitrogen Atmosphere

作　　者：魏军从[1] 高春辉[1] 黄建坤[1] 吉秀梅[1] 艾丽[1] 涂军波[1] 

机构地区：[1]河北联合大学材料科学与工程学院,河北省无机非金属材料重点实验室,唐山063009

出　　处：《硅酸盐通报》2013年第8期1602-1605,1613,共5页Bulletin of the Chinese Ceramic Society

基　　金：河北省自然科学基金资助项目(E2012401054)

摘　　要：为了研究氮气气氛下MgAl2O4/SiC材料的反应性能及硅粉的影响,将添加硅粉前后的MgAl2O4-SiC材料在流动氮气中经1600℃保温3 h烧成,对烧结后的试样进行XRD、SEM和EDS分析。研究发现:两者材料的主要物相均为镁铝尖晶石、碳化硅、氮化硅。不添加硅粉的试样中生成的氮化硅呈长径比较大的纤维状,其生长过程符合VS生长机制;添加硅粉后的试样中生成的氮化硅根部呈柱状,顶部呈锥状,其生长是LS和VS生长机制共同作用的结果。另外,氮化烧成时MgAl2O4/SiC反应界面层中会发生离子互扩散,可能生成少量堇青石,并且C4-、Al3+、Mg2+较O2-、Si4+具有更大的扩散速度。Abstraet：MgAl2O4-SiC composites were prepared by using silicon powder （0, 5wt% , respectively） as additive and being fired at 1600 ℃ for 3 h in flowing nitrogen. The reactivity between MgAl2O4 and SiC and the effects of the addition of silicon powder were investigated. The phase of MgAl2O4-SiC composites were investigated by means of X-ray diffraction microscopy （SEM） coupled with energy for the two specimens, the main phases composition, microstructure （XRD）, scanning electron dispersive X-ray spectroscopy （EDS）. The results showed that were both magnesia aluminate spinel, silicon carbide and silicon nitride. The silicon nitride formed in specimens without silicon powder presented fibrous length-diameter ratio. The crystal growth process accorded with vapor solid growth shape with large mechanism ; the specimens with addition of silicon powder produced silicon nitride of cylindrical root and conic top. The crystalline growth process accorded with liquid solid mechanism and vapor solid mechanism. During sintering in nitrogen, the interface between MgAl2O4 and SiC would take place ions interdiffusion and few cordierites were formed. Furthermore, C^4- , Al^3＋ and Mg^2＋ ions had bigger diffusion velocity than O^2- and Si^4＋ ions.

关 键 词：MgAl2O4-SiC材料 氮气气氛 氮化硅 生长机制 

分 类 号：TB332[一般工业技术—材料科学与工程]