LAUSR

Abstract With the aim to optimize the microstructure and thermo-mechanical properties of MgO-based dry vibratable material (DVM), metal Fe was introduced as a novel sintering aid and its effect on the physical and mechanical properties, refractoriness under load, as well as creep behavior was investigated. A liquid phase sintering mechanism and limited solid-solid bonding were identified for the traditional MgO-based DVM, which resulted in a low recommended working temperature (T0.5, 1452 °C) and a high creep rate. The poor resistance to thermo-mechanical stress should be responsible for the severe erosion of tundish linings. For the Fe-containing refractory, however, effective solid-state sintering occurred owing to the formation of (Mg,Fe)Oss and MgFe2O4. As a consequence, both densification and direct bonding were greatly improved. Moreover, excellent thermo-mechanical properties were also obtained, achieving an increase of 100 °C in T0.5 and a decrease of 90% in creep rate at stationary stage compared to the traditional one. The changes in bonding type, porosity, and distribution of the liquid phases are considered as the main mechanisms for the long-term structural stability.