摘要 |
<p>Oxide refractory materials (for example, alumina-zirconia mixtures) can be cast by a semicontinuous process to have an extremely fine crystal structure, by casting a melt of the oxide refractory materials onto a non-reactive, non-melting particulate solid cooling media of a material other than that of the oxide refractory material (for example, steel spheres having a size ranging from about 5 to about 60 mm), additional cooling media being added to the solidification chamber while the oxide refractory melt is cast onto the cooling media. The melt is then cast upon the additional cooling media, until the solidification chamber is nearly filled with both oxide refractory material and cooling media. The solidified material, when crushed and graded, has exceptional utility as an extremely tough abrasive grain.</p> |