Multiphase composites obtained by sintering reaction of boehmite and zircon part I: Development and microstructural characterization

Abstract

In this work, different composites (zircon-mullite, zirconia-mullite-zirconia, mullite-zirconia and alumina-zirconia-mullite) were developed by reactive sintering of a powder mixture of boehmite (AlOOH)) and zircon (ZrSiO) 4 . These powder mixtures were mixed and ground by ball milling and then pressed in cylindrical form. Finally, the green specimens were sintered in air during 2 hours between 1400°C and 1600°C, with a heating and cooling rate of 5°C/min. The dilatometric curves show that there are several microstructural transformations in these mixtures. X-rays diffraction spectra showed formation of several composites depending on the initial conditions (% of boehmite and zircon and sintering temperature). The micrographic observations of the samples confirmed the presence of various phases.