7621. CO 2 laser treatment of As-S chalcogide thin films : A M Adriesch et al, J Appl Phys, 65, 1990, 7536–7541

Abstract

Slag-resistant tests were performed in fired crucibles made from raw kaolin and calcined alumina powders containing 65, 72, 78 wt% Al2O3 and 65 wt% Al2O3 + 6 wt% Cr2O3. The crucible tests showed that a 2-mm-wide protective layer was visible between slag and non-reaction zones in the 65 wt% Al2O3 crucible and that no such layer appeared in the 72 and 78 wt% Al2O3 crucibles. Reflected light microscopy revealed that in the 65 wt% Al2O3 + 6 wt% Cr2O3 crucible the slag zone was less fluid and the reaction zone less slag penetrative and reactive, as compared with others. The expansion or the shrinkage trend of the bauxite aggregate brick bonded with raw kaolin and calcined alumina powders after more than 3 h reheating at 1500°C depends mainly on the alumina content of the bonding matrix regardless of aggregate mix grading, and previous firing temperatures for green compacts. The continuing positive reheat linear change of bauxite-based, high-alumina, torpedo ladle brick, which promotes mortar joint tightening and retards pencilling slag attack, can be obtained by the combined action of the bonding matrix containing 65 wt% Al2O3 and a lower temperature firing prior to services.