Refractory Compositions Designed for Highly Heat-Resistant Ceramic Molds in Foundry Practice

Resumo

Sintering peculiarities of ceramics prepared by semidry pressing were investigated. The fillers were Y₂O₃ and fused corundum α-Al₂O₃ . The binders were pure or Y- or Mg-modified alumoxane. The mechanism of sintering processes in the studied ceramic at various temperatures and its influence on the properties of the resulting ceramic were analyzed. The phase composition and thermomechanical properties of test ceramics prepared at 1500°C were studied. Prepared test ceramic crucibles had improved heat resistance and were robust to thermal cycling. The possibility of using the developed ceramic crucibles for melting and casting of chemically active and highly heat-resistant metals and alloys was discussed.