Refractory object, glass overflow forming block, and process for glass object manufacture

Abstract

A refractory object can include at least 10 wt % AlO. In an embodiment, the refractory object can further include a dopant including an oxide of a rare earth element, Ta, Nb, Hf, or any combination thereof. In another embodiment, the refractory object may have a property such that the averaged grain size does not increase more than 500% during sintering, an aspect ratio less than approximately 4.0, a creep rate less than approximately 1.0×10μm/(μm×hr), or any combination thereof. In a particular embodiment, the refractory object can be in the form of a refractory block or a glass overflow forming block. The glass overflow forming block can be useful in forming an Al—Si—Mg glass sheet. In a particular embodiment, a layer including Mg—Al oxide can initially form along exposed surfaces of the glass overflow forming block when forming the Al—Si—Mg glass sheet.