Enhanced service performances of in-situ Mg-Sialon/MgAl2O4 folding structure in low carbon Al2O3–C refractories: Phase reconfiguration of nano-MgSiN2

Abstract

The utilization of in-situ ceramic combination effectively addressed the issue of weak bonding at the interface in low carbon Al2O3–C refractories, enhancing the material service performances. In this study, nano-MgSiN2 synthesized from molten salt was utilized for incorporation of Al2O3–C refractories, as well as in assessment of mechanical properties, thermal shock stability, oxidation resistance and corrosion resistance. The findings demonstrate that the molten salt medium can lower synthesis temperature and decrease particle size of nano-MgSiN2. In addition, nano-MgSiN2 undergone phase reconfiguration at 1500 °C to form Mg(g) and Si3N4(s). The folding structure Mg-Sialon/MgAl2O4 were formed through phase reconfiguration of Mg(g) and Si3N4(s). This change enhanced interfacial bonding strength of Mg-Sialon/Al2O3 and MgAl2O4/Al2O3. The mechanical properties and thermal shock stability of refractories were enhanced by novel reconfiguration technology, resulting in CCS value of 176.9MPa. Simultaneously, Mg-Sialon transformation facilitated the interconnection of the oxide layer, enhancing oxidation resistance and corrosion resistance.