The influence of nanoparticles and functional metallic additions on the thermal shock resistance of carbon bonded alumina refractories

Modern steel casting plants require functional refractory components such as monobloc stoppers, submerged entry nozzles, and ladle shrouds. The functional flow control components in steel casting plants are often made of carbon bonded alumina refractories containing approximately 30% residual carbon after coking. This study investigated the mechanical and thermo-mechanical behavior of different functionalized Al2O3–C materials with additions based on alumina nanosheets, carbon nanotubes, semiconductive silicon, and a carbon content reduced to 20%. Furthermore, the curing temperature and the mixing order of the raw materials were altered. By optimizing the curing and mixing conditions of the samples that included all the additives, high residual strengths (with absolute values of up to 14.51 MPa before thermal shock, after the first thermal shock, 12.11 MPa, and after the fifth thermal shock, 13.87 MPa, and a relative values of up to −19.81% and −4.29% respectively) could be recorded after thermal shock treatment.