Fabrication of TiB-reinforced titanium matrix composite via spark plasma sintering and vertical bidirectional reactive hot rolling

Abstract

TiB/Ti6Al4V composite was prepared using spark plasma sintering followed by bidirectional reaction hot rolling. The TiB whiskers were synthesized in situ during the rolling process, thereby preserving a relatively high structural integrity. TiB whiskers were distributed within the composite in three distinct locations: intragranular, intergranular, and transgranular distribution. After eight passes of vertical bidirectional reaction hot rolling, the average grain size of the matrix was refined to 1.36 μm, and the grains exhibited random crystallographic orientations. Tensile properties in different directions demonstrated high consistency, with a strength of 1220 MPa ± 30 MPa and an elongation of 8.0% ± 0.5%. The primary strengthening mechanisms in the composite included grain refinement, dislocation strengthening, and load transfer strengthening from the TiB.