Synthesis and Consolidation of Nanostructured Nb₂C-Al₂O₃ Composite.

Although an extremely hard ceramic material, niobium carbide has low fracture toughness to use wide applications. To fabricate nanostructured composite is common method to improve fracture toughness. Nanopowder mixture of Nb2C and Al2O3 were synthesized according to the reaction (Al4C3 + 6Nb + 3O(2) -> 3Nb(2)C+ 2Al(2)O(3)) from Al4C3 and Nb powders by high-energy ball milling. The synthesized mixture of Nb2C and Al2O3 powders was consolidated by pulsed current activated sintering method within two min under the 80 MPa pressure. Nb2C and Al2O3 in the composite were nano-sized phases. The fracture toughness of a nanostructured Nb2C-Al2O3 composite of this study is better than that of previous study.