Superplastic tensile characteristics of in situ TiBw/Ti6Al4V composites with novel network microstructure

In situ TiB whiskers reinforced Ti6Al4V (TiBw/Ti64) composites were fabricated by tailoring a novel network microstructure—which improved the strengthening and toughening effects of titanium matrix composites (TMCs). Superplastic tensile deformation of the composites was carried out at 900–1000 °C and 0.0005–0.01 s−1. The results showed that the tensile elongation of the novel composites is over 100%, even up to 214% at 940 °C. The strain rate sensitivity (m) and the activation energy (Q) of the novel composites are 0.25 and 338 kJ/mol, respectively. These phenomena indicate that the novel composites possess an improved deformability. The superplasticity of the TiBw/Ti64 composites can be attributed to the novel network microstructure, which can induce superior deformability by inhibiting local deformation, decreasing crack propagation rate and refining grain size.