Propiedades mecánicas y coeficiente de dilatación térmica de la β-eucriptita sinterizada por la técnica de microondas

Abstract

Microwave non-conventional sintering technique allows obtaining fully dense glass-free β-eucryptite bulk material (~99 %). A considerable difference in the densification, microstructure, coefficient of thermal expansion behaviour and mechanical properties, between conventional and non-conventional sintered specimens was observed. The hardness and Young's modulus values obtained by microwaves at 1200 °C-5min have been relatively high, 6.8 GPa and 101 GPa, respectively, compared to conventional sintering (3.9 GPa and 58 GPa, respectively). Very low thermal expansion materials have been obtained in a wide temperature range including cryogenic temperatures (from -150 °C to 150 °C). The high heating rate along with the lower energy consumption makes microwave technique a clear alternative to other types of sintering methods.