A short and long range study of mullite–zirconia–zircon composites

N. RENDTORFF; M.C. CONCONI; E. AGLIETTI; YAMIL CHAIN; ALBERTO PASQUEVICH; PATRICIA RIVAS; JORGE MARTINEZ; MARIA C. CARACOCHE

HYPERFINE INTERACTIONS

SPRINGER

Año: 2010 vol. 198 p. 219 - 228

0304-3843

Abstract In the field of refractory materials, ceramics containing mullite–zirconia are the basis of those most used in the industry of glass and steel. It is known that the addition of zircon improves the behavior of the refractory used in service. Knowing that some mullite–zirconia composites properties as fracture strength and the elastic modulus E are associated with the material microstructure integrity, the eventual thermal decomposition of zircon into zirconia and silica could seriously alter the material elastic properties. In this paper the phase content of a series of mullite–zirconia–zircon (3Al2O3.2SiO2–ZrO2–ZrSiO4) composites is determined at atomic level via perturbed angular correlations (PAC) and compared with that derived from the long range X-ray diffraction technique. PAC results on the asprepared materials indicate that all nominal zircon is present and that it involves two types of nanoconfigurations, one of them describing aperiodic regions. The thermomechanical properties already reported for these materials could be related to the crystalline to aperiodic zircon concentrations ratio they exhibit.