Characterization of tensile properties and fracture mechanism of high ductility TZM-Y2O3 composite fabricated by SPS

To address the high brittleness and insufficient toughness of Titanium-Zirconium-Molybdenum (TZM) composites, this study successfully prepared a TZM-0.5 wt.% Y 2 O 3 composite with high ductility using spark plasma sintering (SPS), and systematically investigated the influence of sintering temperature on its tensile properties and fracture mechanism. At 1900 °C, the composite grains are refined to 3.75 μm, the relative density reaches 99.2 %, and the hardness is 214.2 HV 0.2 . Its room-temperature yield strength (YS), ultimate tensile strength (UTS), and elongation (EL) reach 548 MPa, 631 MPa, and 18 % respectively, with a strength-ductility product (PSE) of 11.4 GPa·%, exhibiting a ductile fracture feature dominated by microporous aggregation. Compared with the samples sintered at 1800°C, those sintered at 1900°C have finer and more uniform grains, as well as higher density. However, the mechanical properties of the samples sintered at 2000°C show a slight decrease, which is caused by the over-sintering behavior. The composite sintered at 1900°C exhibits the optimal matching between microstructure and mechanical properties. Its excellent performance stems from the synergistic effect of dispersion strengthening by nanoscale second phase particles within grains and grain refinement strengthening.