Threshold conversion for field emission scanning electron micrograph of glass-alumina composites in determining the activated interfaces

Abstract

Activated alumina interfaces in glass-alumina composites during isothermal sintering at 710°C by a novel colloidal processing was extracted by the threshold conversion of the micrograph obtained by a field emission scanning microscope. The relative ratio of the activated alumina interfaces in the final stage of sintering to that in the initial stage of sintering was calculated. The kinetics equations of both the evolution for the activated alumina interfaces during isothermal sintering and its effect on the linear shrinkage of the glass-alumina composites were established. The results show that the activated alumina interfaces in the final stage of sintering are 1.256 times more than that in the initial stage of sintering. The increased alumina interfaces decreases the total shrinkage rate of the glassalumina composites, in which a particular obstruction of the viscous flow of the glass matrix is suggested.

Keywords

• glass-alumina composites
• isothermal sintering
• activated interfaces
• threshold conversion
• field emission scanning electron microscopy