CHEMICAL DIFFUSION AND CRYSTALLINE NUCLEATION DURING OXIDATION OF FERROUS IRON-BEARING MAGNESIUM ALUMINOSILICATE GLASS

被引:90
作者
COOK, GB [1 ]
COOPER, RF [1 ]
WU, T [1 ]
机构
[1] CORNELL UNIV,DEPT MAT SCI & ENGN,ITHACA,NY 14853
基金
美国国家科学基金会;
关键词
Chemical Diffusion - Crystalline Nucleation - Ferrous Iron Bearing Glass - Glass Ceramics Formation - Glass Devitrification - Magnesium Aluminosilicate Glass;
D O I
10.1016/0022-3093(90)90205-Z
中图分类号
TQ174 [陶瓷工业]; TB3 [工程材料学];
学科分类号
0805 ; 080502 ;
摘要
Rutherford backscattering spectroscopy (RBS) and transmission electron microscopy (TEM) have been used to evaluate the mechanism and kinetics of oxidation of a Fe2+-doped MgOAl2O3SiO2 glass (with nominal composition along the enstatite-cordierite-liquid divariant) which was heat treated in air under the time and temperature ranges 10-150 h and 700-800°C, respectively. The results clearly demonstrate that oxidation occurs by a cation diffusion process: specifically, the divalent cations diffuse from the interior of the glass to the free surface where they subsequently react with environmental oxygen to form a two-phase, MgO(Mg, Fe)3O4 crystalline layer which covers the (divalent cation-depleted) glass. Oxidation of some Fe2+ within the glass occurs via the inward flux of electron holes (a counterflux to the divalent cation diffusion required to maintain charge neutrality of the glass); this internal oxidation results in the fine-scale (∼ 1-5 nm), homogeneous nucleation of crystalline (Mg, Fe)3O4 within the divalent cation-depleted layer of the glass. Chemical diffusion of an oxygen species is thus demonstrated to be a slower, parallel kinetic process which is not required for oxidation to occur in this material. A first-order analysis of oxidation kinetics in the glass is presented. © 1990.
引用
收藏
页码:207 / 222
页数:16
相关论文
共 47 条
[41]  
Wendlandt R. F., 1980, EOS T AM GEOPHYS UN, V61, P1142
[42]  
WILLIAMSON J, 1986, J IRON STEEL I, V206, P898
[43]  
WINCHELL P, 1969, HIGH TEMP SCI, V1, P200
[44]   RUTHERFORD BACKSCATTERING SPECTROSCOPY STUDY OF THE KINETICS OF OXIDATION OF (MG,FE)2SIO4 [J].
WU, T ;
KOHLSTEDT, DL .
JOURNAL OF THE AMERICAN CERAMIC SOCIETY, 1988, 71 (07) :540-545
[45]  
YINNON H, 1980, PHYS CHEM GLASSES, V21, P204
[46]  
ZALAZINSKII AG, 1975, ZH FIZ KHIM+, V49, P914
[47]  
ZIEGLER JF, 1982, IBM RC9250 RES REP