In-Situ Reactions and Properties of Alumina-Magnesia Refractory Castables with Addition of TiO_2

摘要

In the present work, the phase composition, apparent porosity, permanent linear change and microstructure were examined in castables containing 0-2 mass-% of TiO_2 with and without magnesia to investigate the effect of TiO_2 on in-situ reactions and properties in alumina-magnesia refractory castables after calcination at 1450 °C/5 h. The results show that the addition of TiO_2 can modify in-situ reactions and sintering processes. The amounts of spinel and calcium hexaaluminate (CA_6) formed in overall castables increased with TiO_2 addition, and the grain size of CA_6 decreased gradually. The difference of the phase composition in overall and the matrix of castables indicated that the aggregates were involved in the CA_6 formation. The permanent linear change and cold modulus of rupture of castables were dependent on TiO_2 addition. For design of alumina-magnesia refractory castables, TiO_2 could be used as an alternative to achieve good strength and certain expansion.