Recrystallization Behavior of Ti-6.5Al-3.5Mo-1.5Zr-0.3Si Alloy under Electroshocking Treatment

In this work, a novel electroshocking treatment (EST) method is employed to modify the microstructure of Ti-6.5Al-3.5Mo-1.5Zr-0.3Si alloy. The microstructural morphology and texture distribution after EST are characterized and analyzed to study the recrystallization behavior of the titanium alloy. After EST with 0.04 s, secondary alpha s phase transforms into beta phase. After EST with 0.06 s, surrounding the alpha p phase, a significant amount of needlelike martensitic phase (alpha M) precipitates. Electron backscatter diffraction results reveal that EST reduces intragranular orientation gradients, resulting in a convergence of each point orientations within individual grains. Under longer EST time, grain boundaries display greater irregularity. After EST with 0.05 s, partial recrystallization takes place, and with an increase of EST time to 0.06 s, all deformed grains undergo complete recrystallization, forming defect-free recrystallized grains. A substantial enhancement in texture intensity for both alpha and beta phases, exhibiting prominent preferred orientations, and the increase in hardness values is contributed to the precipitation of alpha M phase. The stress analyses indicate that EST can optimize the distribution of residual stress and offer a potential solution for improving fatigue performance. In all results, it is shown that EST is an effective approach for manipulating the microstructure and optimizing the residual stress distribution of titanium alloys. A novel treatment of electroshocking treatment (EST) is adopted to optimize the microstructure and improve the mechanical properties of Ti-6.5Al-3.5Mo-1.5Zr-0.3Si alloy. In the results, it is shown that the martensite phase alpha M is precipitated around the alpha p phase after EST with 0.06 s. Prolonging EST duration, the fractal dimension of grains increases, the grain boundaries become complex, and the deformed grains undergo recrystallized behavior.image (c) 2024 WILEY-VCH GmbH