Characterization and Microstructure of Kaolin-Based Ceramic Using Geopolymerization

Abstract

Geopolymers can be transformed into ceramics upon sintering. This paper reports the effect of temperature on the physical, mechanical properties and characteristics of kaolin geopolymer ceramic. The nepheline ceramic was fabricated through geopolymerization. The geopolymer samples were exposed to temperature from 900 °C up to 1200 °C. Kaolin geopolymer undergo shrinkage upon temperature exposure. Unheated kaolin geopolymer appeared to be amorphous and crystalline nepheline was the major phase after sintered to high temperatures as depicted by XRD analysis. Microstructural analysis showed formation of denser structure as the temperature increased. The maximum flexural strength of 86 MPa is achieved at temperatures of 1200 °C.