Fabrication of high-performance (TiC + (TiZr)5Si3)/TA15 composites via spark plasma extrusion

To address the room-temperature brittleness of (TiC + (TiZr)5Si3)/TA15 composites, this study introduces a novel thermomechanical approach—spark plasma extrusion (SPE). The microstructure and mechanical properties of the extruded samples were systematically evaluated. The extruded composites exhibited a yield strength of 1267 MPa, an ultimate tensile strength of 1383 MPa, and an elongation of 7.0%, all markedly superior to those of the as-sintered counterparts. The enhanced ductility is attributed to the more homogeneous distribution of TiC and (TiZr)₅Si₃ reinforcements and the activation of additional <c + a> dislocations during deformation. Furthermore, at 600, 650, and 700 °C, the tensile strengths of the extruded composites reached 840, 652 , and 480 MPa, respectively, representing increases of 75.9%, 53.1%, and 44.0% over the TA15 alloy. During high-temperature tensile tests, matrix softening facilitated greater ductility, with dislocation slip identified as the dominant deformation mechanism. This study provides a new and feasible approach for the fabrication of high-strength, high-ductility titanium matrix composites.