Abstract
The mechanical strength of MgO-C brick which incorporated MgO supported carbon nanofibers （CNF-MgO composite） was investigated by the three-point bending test. The results show that the strength of the brick
increased with increasing the CNF-MgO composite content. Especially when the CNF-MgO composite content was 6mass%, the strength was high about 2.2 times compared to the material without the CNF-MgO composite. In addition, combinational effects of adding the CNF-MgO composite with aluminum and pitch were also investigated. As a result, the strength was remarkably improved by the addition of the CNF-MgO composite with aluminum and the effect of pitch addition on the lowering the modulus of elasticity was maintained when the CNF-MgO composite added in the MgO-C brick. The SEM image of specimen shows that the CNFs with net-like structure existed in the matrix of the MgO-C brick. The mechanism of strength improvement was suggested that it caused by crack arresting effect of the CNFs in MgO-C bricks.
