Influence of h-BN particle size on fracture behavior and thermal shock resistance of Al2O3–C refractories
Zi-xu Ji1, Wen-jing Liu1, Ning Liao1,2, Ya-wei Li1,2,3, Tian-bin Zhu1,2
1 The State Key Laboratory of Refractories and Metallurgy, Wuhan University of Science and Technology, Wuhan 430081, Hubei, China 2 National-Provincial Joint Engineering Research Center of High Temperature Materials and Lining Technology, Wuhan 430081, Hubei, China 3 School of Chemical Engineering, Qinghai University, Xining 810016, Qinghai, China
Abstract：h-BN can be applied in Al2O3–C refractories to substitute graphite due to their similar crystal structure and better resistance to molten steel and oxidation. The effects of h-BN particle size on the mechanical properties and fracture behavior of Al2O3–C refractories were investigated through wedge splitting test and microstructural analyses. The obtained results demonstrated that the addition of larger-sized h-BN was conducive to the growth of in situ formed SiC whiskers, which contributed to the highest flexural strength (42.63 ± 3.10 MPa) of specimen D10. In comparison, the smaller-sized h-BN can induce more crack propagation paths along the interface and within matrix, leading to more tortuous crack propagation paths, and thus the thermal shock-related parameters such as specific fracture energy, characteristic length, and thermal shock resistance were improved. Consequently, the residual strength ratio of Al2O3–C refractories was increased from 35.5% to 42.5% with decreasing the h-BN particle size from 10 to 0.1 μm.
Zi-xu Ji,Wen-jing Liu,Ning Liao, et al. Influence of h-BN particle size on fracture behavior and thermal shock resistance of Al2O3–C refractories[J]. Journal of Iron and Steel Research International, 2022, 29(7): 1129-1137.
2022, Vol. 29 
