Correlation Study on the Effect of Sintering Mechanism with the Properties of Geopolymer-Based Ceramic

Nepheline geopolymer-based ceramics are emerging as a promising alternative to traditional ceramics due to their eco-friendly production and sustainable nature. Therefore, this study aims to comprehensively investigate the relationship between mechanical behaviour and sintering mechanisms in the production of kaolin geopolymer-based nepheline ceramics. Sodium hydroxide and sodium silicate were mixed to act as the alkaline activator to facilitate the geopolymerization process. The experimental analysis involved varying the sintering temperature within the range of 200°C to 1200°C. The findings from the correlation study highlight that the flexural strength and densification process is in linear relation with R2 of 0.9369, whilst the water absorption and volumetric shrinkage exhibited an inversely linear relationship with the R2 value of 0.8733. The maximum flexural strength of 78.92 MPa and density of 2.56 g/cm3 were achieved when sintered at 1200°C. Meanwhile, the water absorption decreases with the increase of volumetric shrinkage, which might relate to the densification process of the geopolymer-based nepheline ceramic. The outcome of this research contributes a deeper understanding of the interplay between mechanical behaviour and sintering mechanism, enabling the design of superior sintered materials.