Preparation, properties, and interfacial bonding mechanism of MgO–Mg2SiO4–SiC–C refractories

Abstract

Because the thermal shock resistance of MgO–C refractories decreases with carbon content, the development of new high-performance magnesia based refractories is necessitated. In this study, MgO–Mg2SiO4–SiC–C refractories with low carbon content and high thermal shock resistance were prepared using MgO–Mg2SiO4 as the aggregates and MgO–SiC–C as the matrix. Based on the analysis of the Hasselman thermal shock stability factor, the thermal shock resistance of the MgO–Mg2SiO4–SiC–C refractories was enhanced by reducing the thermal expansion coefficient, increasing the elastic modulus, and improving the fracture toughness. Molecular dynamics simulations of the dynamic process of interface bonding varying with temperature showed that SiC and Mg2SiO4 in MgO–Mg2SiO4–SiC–C refractories could serve as media for indirectly binding MgO and C, thus forming a network that effectively strengthened the refractories.