Oxidation resistance, residual strength, and microstructural evolution in Al2O3-MgO–C refractory composites with YAG nanopowder

•A novel oxidation resistant refractory composition with YAG was proposed.•Oxidation index was reduced from 68 % to 27 % at 1600 °C.•Rate constant was decreased from 7.76 × 10−3 to 1.64 × 10−3 cm2 min−1 at 1600 °C.•Residual strength data indicated ∼70 % improvement in thermal shock resistance.•Improvements were ascribed to the YAG/Spinel composite bonding microstructure.