Creep behavior and physical characterization of fusion-cast alumina refractories

Fusion-cast alumina refractories have become a popular choice for crowns and side-walls in oxy-fueled glass furnaces due to their homogeneity, low porosity, high refractoriness, low levels of glassy phase, and good spall resistance. Yet, published engineering creep and high temperature modulus of elasticity data are essentially nonexistent for commercial refractories used in such applications in the glass industry. Results from research at the University of Missouri--Rolla and Oak Ridge National Laboratory on measurements of creep, physical, and microstructural characteristics are discussed, along with basic modeling of exhibited behavior and limitations of fusion-cast alumina refractories. Such physical characterization as density/porosity measurement, chemical analysis, microstructural analysis, elastic modulus, thermal expansion, thermal stability, and thermal conductivity were performed both at room temperature and elevated temperatures. Creep measurements were performed at stresses ranging from 0.2 - 0.6 MPa and temperatures from 1450 - 1650°C using a pneumatically controlled compressive creep frame and electrically heated furnace --Abstract, page iii