Characterization and interfacial reinforcement mechanism of MgO/FHZC refractory composite

A MgO-based fused high-zirconia-coated (MgO/FHZC) refractory composite was developed for low-carbon long-life refractory linings in high-temperature industrial furnaces. The MgO/FHZC refractory composite was prepared by electroforming. The interface of the MgO/FHZC refractory composite is tightly bonded with no obvious layered interfaces. Some of the Mg 2+ entered the Zr 4+ lattice to form a c-Zr 0.86 Mg 0.14 O 1.86 substitutional solid solution. The interfacial bonding strength is enhanced by the precipitation of spherical MgO grains at the grain boundaries and pores. The oxygen vacancies generated through the dissolution of Mg 2+ in the ZrO 2 lattice resulted in the formation of micron-sized pores at high temperatures. These pores improve the thermal shock resistance of the composite and reduce its thermal conductivity. The MgO/FHZC refractory composite has excellent corrosion resistance because of its non-reactivity with liquid glass and CaO–Al 2 O 3 -based slag with higher Al 2 O 3 content in the range of 25 wt% to 40 wt%. It therefore has broad application prospects in high-temperature industrial processes such as glass and steel production.