In situ preparation of TiB nanowires for high-performance Ti metal matrix nanocomposites

High-performance Ti-based nanocomposites reinforced with TiB nanowires with a network-woven structure were fabricated, and the growth of the TiB nanowires was investigated through comparative sintering and annealing experiments. TiB nanowires nucleated from the surfaces of the Ti powder particles and then grew into the particles. They remained stable in the Ti matrix when isothermally annealed at 1000 °C for 24 h, but coarsened noticeably during rapid heating to 1200 °C. The coarsening of the TiB nanowires was found to occur through stacking of thinner TiB nanowires, which can be regarded as a detachment-attachment controlled Ostwald ripening process and is affected by the surface free energy of the faceted TiB. Tensile property tests revealed that TiB nanowires are distinctly advantageous over TiB microwhiskers in strengthening the Ti matrix. The as-sintered Ti-based nanocomposites achieved both high tensile strengths ( > 800 MPa) and excellent tensile ductility ( > 20%).