Changes in the Structure and Mechanical Properties of Submicrocrystalline Titanium during Deformation in a Temperature Range of (0.15-0.45)T_m

摘要

The structure of VT1-0 titanium in the submicrocrystalline (SMC) state and changes in its structure and mechanical properties during deformation in a temperature range of (0.15-0.45)T_m have been studied. The formation of an SMC structure in titanium via warm severe plastic deformation is accompanied by dynamic strain aging (DSA). The development of DSA in a temperature range of 300-425 deg C leads to anomalous changes in its mechanical properties: decreasing plasticity, an increase in the flow stress, and an increase in the rate of strain hardening. The mechanical properties and activation energies obtained demonstrate that SMCVT1-0 titanium shows signs of superplasticity in a narrow temperature-strain rate range. The lower temperature boundary is limited by the development of DSA, and the upper boundary, by the instability of the SMC structure.