Influence of solid-to-liquid ratio on properties of fly ash geopolymer ceramics

Abstract

Ceramics has come to be progressively very important in industry because of their exceptional mechanical and physical properties The motivation to develop fly ash geopolymer ceramics was to overcome the problem associated with the conventional technical ceramics like alumina, silicon, carbide, aluminium nitride that fracture easily under mechanical or thermo-mechanical loads. The novelties of this research were providing new material to fabricate geopolymer as ceramic precursor and move towards green technology. Geopolymer substrates were activate by adding the alkaline activator gradually with different ratios of solid to liquid ranged from 0.5, 1.0, 2.0 and 3.0 into fly ash at ambient temperature. The samples were cured before undergo powder metallurgy method. The best and optimum solid to liquid ratio is determined at ratio 2.0 based on flexural strength. The broad, amorphous peak showed by phase analysis indicates that geopolymerization has occurred. The formation of almost fully crystalline phase such as albite has been detected which contributes to the flexural strength of fly ash geopolymer ceramic. Microstructure image shows smoother and complete geopolymer matrix which gives denser structure as supported by the excellent density.