The Effect of Annealing on the Mechanical Properties and Microscopic Mechanism of Ti60 Sheet

This study systematically investigated the mechanical properties and microstructural evolution of Ti60 sheets subjected to annealing treatments across a temperature range of 740–880 °C (at 20 °C intervals) through comprehensive characterization techniques, including uniaxial tensile testing, optical microscope, scanning electron microscope, electron backscatter diffraction (EBSD), and energy dispersive spectroscopy. Notably, within the critical temperature window of 780–840 °C, a concurrent reduction in both yield strength and elongation is observed, deviating from the conventional strength‐ductility trade‐off relationship typically exhibited by metallic materials. The strength degradation is attributed to the reduction of dislocation density in the material. Fractographic examination consistently demonstrates brittle fracture characteristics, with a progressive decline in ductility correlating with increasing annealing temperature. In near‐α titanium alloys, prismatic slip systems exhibit the lowest critical resolved shear stress at ambient temperature. The reduced activation of prismatic slip systems after 840 °C annealing compared to 780 °C treatment serves as the primary factor responsible for the deterioration of plasticity.