Enhanced thermal shock resistance of low‐carbon MgO–C refractories with SiC/MgAl ₂ O ₄ nanocomposite powder

Abstract To enhance the thermal shock resistance of low‐carbon MgO–C refractories, SiC nanowires incorporated SiC/MgAl 2 O 4 composite reinforcer were introduced. The effect of SiC/MgAl 2 O 4 on the mechanical properties, thermal shock resistance, oxidation resistance and slag resistance of low‐carbon MgO–C refractories was explored. The results showed that the low‐carbon MgO–C sample incorporated with 9 wt.% SiC/MgAl 2 O 4 (M9) displayed optimal overall properties, with 28% higher residual strength ratio, 59% lower oxidation index, and 18% reduced corrosion area compared to the reference sample M0. The increased residual strength ratio is mainly attributed to the synergistic effect of SiC nanowires and rod‐shaped MgAl 2 O 4 , which facilitate crack deflection and branching, and energy dissipation through bridging and pull‐out mechanisms, collectively contributing to matrix toughening. Besides, M9 (3 wt.% graphite) demonstrates better mechanical strength, oxidation resistance, and slag resistance compared to high‐graphite samples (10 wt.% graphite), highlighting the significant potential of SiC/MgAl 2 O 4 composite reinforcer in developing sustainable low‐carbon refractories.