| Title | Improved Oxidation Resistance and Mechanical Properties of Al2O3-C Refractories with Addition of Boron-doped Expanded Graphite |
| Thematic area | Raw Materials |
| Presenter | Dr. Qinghu Wang |
| Authors | Dr. Qinghu Wang, The State Key Laboratory of Refractories and Metallurgy, Wuhan University of Science and Technology, Wuhan - China Prof. Yawei Li, The State Key Laboratory of Refractories and Metallurgy, Wuhan University of Science and Technology, Wuhan - China Mr. Shaobai Sang, The State Key Laboratory of Refractories and Metallurgy, Wuhan University of Science and Technology, Wuhan - China Mr. Yibiao Xu, The State Key Laboratory of Refractories and Metallurgy, Wuhan University of Science and Technology, Wuhan - China |
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Abstract
Born (B)-doped expanded graphite (EG) has been synthesized by annealing the synthetics, which were obtained from the suspensions of EG and boric acid. After that, the B-doped EG were introduced into Al2O3-C refractories to partially replace graphite flake. The ratio of the G and D bands of B-doped EG in first-order Raman spectra curves was significantly larger than as-received EG, indicating more graphitization of B-doped EG due to doping effect. Meanwhile, the B1s XPS spectrum of B-doped EG could be composed of several peaks at 187.2, 188.9 and 190.3 eV, being attributed to the presence of B atom in B4C, B-sub-C and BC2O, respectively. In comparison with as-received EG, the B-doped EG appeared better oxidation resistance via non-isothermal kinetics analysis. In addition, the mechanical properties such as modulus of rupture (CMOR), flexural modulus (FM), force and displacement and thermal shock resistance of Al2O3-C specimens with 0.5 wt% B-doped EG were improved in comparison with those with only graphite flake. Besides, the Al2O3-C specimens appeared significantly better oxidation resistance due to addition of B-doped EG. |
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