Effects of Different Aluminum-Based Materials on Properties and Microstructure of MgO-Al-C Materials

Abstract

Abstract: MgO-Al-C materials were fabricated using sintered magnesia aggregates, fused magnesia fine powder, Al powder, N220 carbon black as raw materials, and phenolic resin as a binder. The effects of three aluminum-based raw materials (granulated alumina micro-powder, alumina hollow micro-beads, calcium hexaaluminate) on the cold modulus of rupture, high modulus of rupture, thermal shock resistance and oxidation resistance of samples were investigated, the phase composition and microstructure were analyzed via SEM and XRD. The results show that granulated alumina micro-powder has a porous structure that can absorb thermal stress inside the MgO-Al-C materials. When the granulated alumina micro-powder is added at 1% (mass fraction, the same below), it can increase the cold modulus of rupture and thermal shock resistance of the MgO-Al-C materials, and significantly improve the oxidation resistance. Alumina hollow micro-beads has a hollow structure, which can buffer thermal stress inside the MgO-Al-C materials. When the added amount of alumina hollow micro-beads is 3%, the cold modulus of rupture of the MgO-Al-C materials can be significantly improved, and the material has high thermal shock resistance and oxidation resistance. Calcium hexaaluminate has a lower coefficient of thermal expansion, which can give the MgO-Al-C materials better toughness. When the added amount of calcium hexaaluminate is less than 5%, the MgO-Al-C materials have better thermal shock resistance.

Key words: refractory, MgO-Al-C material, granulated alumina micro-powder, alumina hollow micro-bead, calcium hexaaluminate, thermal shock resistance, high temperature performance, slide gate

CLC Number:

TQ175.1

HAN Xiaoyuan, SHI Kai, XIA Yi, HONG Siyang, LIU Yang, SHANG Jianzhao. Effects of Different Aluminum-Based Materials on Properties and Microstructure of MgO-Al-C Materials[J]. BULLETIN OF THE CHINESE CERAMIC SOCIETY, 2021, 40(10): 3232-3240.

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