INVESTIGADORES
TOMBA MARTINEZ Analia Gladys
congresos y reuniones científicas
Título:
“Constitutive equations of the creep of cement based magnesia alumina castables with silica fume”
Autor/es:
A.G. TOMBA MARTINEZ; M.A.L. BRAULIO; V.C. PANDOLFELLI
Reunión:
Congreso; International Ceramic Congress CIMTEC 2010; 2010
Resumen:
Alumina-magnesia castables commonly include microsilica in their composition, due its ability to promote better flowability, to inhibit the MgO hydration during curing and drying and to compensate the expansion related to in-situ spinel formation. Therefore, the control of microsilica content stands for a way to design the castable expansion based on microstructural engineering. The presence of microsilica promotes the formation of a viscous phase at high temperature which, beside its effect on the spinel and CA6 formation, affects the deformation ability of the castable. This fact impacts straight in the thermomechanical properties such as creep. In this work, the effect of microsilica on the creep of alumina-magnesia castables were analyzed as a function of the additive content (0-1 wt.%). Cylindrical specimens were prepared according to the 51053 DIN standard and fired at 1550°C for 24 h before testing. Tests were performed in a creep in compression equipment (RUL/CIC Model 421E, Netzch, Germany) at 1450°C for 24 h under a load of 0.2 MPa. Experimental curves were fitted using the q-methodology to obtain constitutive equations and creep parameters. A non-linear regression method was employed and a very good fitting of creep strain data (R2 > 0.99) was obtained. The creep parameters (q1, q2 and q3q4) were correlated to microsilica content and the dominant deformation mechanism operating in the systems.