INTEMA   05428
INSTITUTO DE INVESTIGACIONES EN CIENCIA Y TECNOLOGIA DE MATERIALES
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
HIGH-TEMPERATURE ELASTIC PROPERTIES OF CERAMICS IN THE SYSTEM MgO-Al2O3-SiO2 MEASURED BY IMPULSE EXCITATION
Autor/es:
EVA GREGOROVÁ; WILLI PABST; ANNA MUSILOVÁ; MARÍA ANDREA CAMERUCCI; MARÍA LAURA SANDOVAL; MARIANO HERNÁN TALOU
Reunión:
Conferencia; Seventh International Conference on Materials Structure & Micromechanics of Fracture; 2013
Resumen:
Young´s moduli of talc-based ceramics from the system MgO-Al2O3-SiO2 have been measured for temperatures up to 1000 °C via impulse excitation. It is shown that, after pressing at 50 MPa and firing at 1280 °C, compositions with increased MgO content exhibit higher porosity and lower Young´s moduli (approximately 20-30 % lower than predicted via micromechanical relations). Moreover, while the Young moduli of the base materials decrease with temperature, the Young moduli of the MgO-richer ceramics increase with temperature and exhibit a large hysteresis between heating and cooling. While lower absolute values are mainly due to increased porosity, the reason for the modulus increase with temperature and the hysteresis seems to be the higher content of (proto-) enstatite in the MgO-rich compositions. For a special composition the Young´s moduli have been found to be more or less temperature-independent and without significant hysteresis effects, probably due to the low content of (proto-) enstatite and the high content of sapphirine.