纳米Nd_2O_3对熔融石英析晶机制的影响  

Influence of nano-Nd_2O_3 on crystallization mechanism of fused quartz

作　　者：谷莹蕾[1] 卜景龙[1] 陈越军[1] 马超[2] 王志发[1] 

机构地区：[1]河北联合大学河北省无机非金属材料重点实验室,河北唐山063009 [2]唐山时创耐火材料有限公司,河北唐山060030

出　　处：《耐火材料》2014年第4期249-253,共5页Refractories

基　　金：国家自然科学基金项目(51072046)

摘　　要：利用XRD及Avrami方程对纯熔融石英陶瓷试样N-0与引入3%(w)纳米Nd2O3的熔融石英试样N-3进行等温析晶动力学过程研究。结果表明:两种试样的析晶机制相同,均为表面结构缺陷所致的不均匀成核类型,两种试样的晶粒生长方式均为二维生长伴随有一维及三维的生长方式,但加纳米Nd2O3的试样比不加的一维及三维生长程度更大;纳米Nd2O3的引入减少了熔融石英颗粒表面玻璃结构的"活性成核点",增加了熔融石英颗粒表面玻璃结构的稳定性,使析晶活化能由未加Nd2O3的874 kJ·mol-1提高到1 270 kJ·mol-1,明显降低了熔融石英的析晶率。The isothermal crystallization kinetics of pure fused quartz of blank specimen N-0 and specimen N-3 introducing 3 mass% nano-Nd2 O3 were researched by means of XRD and Avrami equation.The re-sults show that crystallization mechanisms of fused quartz in two specimens are both heterogeneous nucle-ation type caused by surface structure defects,and the grain growth modes of two specimens are both two-dimensional growth accompanied by one-dimensional and three-dimensional growths,but specimen N-3 has the higher degree of grain growth in one-dimensional and three-dimensional than specimen N-0;introducing nano-Nd2O3 can obviously reduce the “active nucleation sites”of glass structure on the fused silica particles surface,enhance the stability of glass structure,increase the activation energy of fused quartz crystallization from 874 kJ·mol^-1 to 1 270 kJ·mol^-1 ,and decrease the crystallization ratio of fused quartz dramatically.

关 键 词：熔融石英 纳米Nd2 O3 析晶机制 动力学 

分 类 号：TQ175[化学工程—硅酸盐工业]