Quasi-static and dynamic mechanical behavior of powder-metallurgy processed Ti−Zr alloys strengthened by Zr-rich laths

Abstract

Ti–Zr alloy with a heterogeneous structure containing Zr-rich laths was prepared using powder metallurgy and hot extrusion processes. The material exhibits an excellent combination of strength and plasticity under quasi-static conditions. A comprehensive investigation of the Ti−Zr alloy was conducted through combined quasi-static (10⁻³ s⁻¹) and dynamic (800−3000 s⁻¹) compression tests across temperatures ranging from 25 to 700 °C, enabling systematic evaluation of competing effects: strain hardening, strain-rate strengthening, and thermal softening. Under dynamic loading at 25 °C, the deformation mechanism is jointly dominated by dislocation slip and twinning, with a flow stress of 1549.1 MPa, exhibiting a significant strain-rate strengthening effect. At high temperatures, the formation of adiabatic shear bands and the thermal softening effect reduce the flow stress of the material and increase the plasticity. The Johnson−Cook (JC) constitutive model was employed to simulate the dynamic stress–strain curves of the Ti−Zr alloy, demonstrating good agreement with experiments at room temperature and intermediate temperatures.