Nano-structured alumina reinforced with NbC

The incorporation of refractory hard particles in alumina-based composites may inhibit grain growth of the matrix, contributing significantly to improve the mechanical properties of the composite. Al2O3-NbC nanocomposites were uniaxially hot-pressed at 1500 °C in an inert atmosphere and their mechanical properties and microstructures were analyzed. Sintered density, microhardness, crystalline phases and mechanical performance were evaluated. X-ray diffraction pattern revealed the presence of Alumina and NbC. No oxidation products were present after the sintering process. Alumina-NbC composite material showed mechanical properties comparable to other alumina-carbide systems. Larger NbC-particles showed to be not effective as grain growth barrier to nano-alumina.