Structural properties of Al2O3–MgO–C refractory composites improved with YAG nanoparticle hybridized expandable graphite

Highlights: • Strong and tough refractories were fabricated. • Weibull modulus (m) was significantly enhanced from 4.2 to 9.8. • Intrinsic surface energy was considerably increased (γ ≈ 11.5 kJ m^-2). • Framework of EG embedded YAG grains was dispersed throughout the microstructure. • Toughening mechanism of new class of EG embedded YAG is proposed. The structural properties of Al₂O₃–MgO–C refractories were measured with the addition of YAG nanoparticle hybridized expandable graphite (EG) powder as a partial replacement of graphite in the refractory composition. The experimental findings showed that the refractories fabricated with YAG nanoparticle hybridized EG exhibited a considerable improvement in structural properties (strength, toughness, Weibull modulus) as compared to that of refractories developed with conventional graphite compositions. These improvements in structural properties can be attributed to the formation of a well-sintered framework of EG embedded polyhedral YAG grains throughout the matrix microstructure of these new class of refractory composites. Mechanisms of microstructure evaluation and toughening in Al₂O₃–MgO–C refractory composites are proposed.