In Situ SEM Compression Study on Micro-mechanical Behavior of Electron Beam Melted Ti-6Al-4V Alloy

Abstract

To investigate the mechanical properties of electron beam melted (EBM) Ti-6Al-4V alloy at the microscale, a series of in situ scanning electron microscope (SEM) compression experiments were performed in the current study. Firstly, a reconstruction of the original β phase of Ti-6Al-4V alloy was conducted using electron backscattering diffraction (EBSD) analysis. Micro-pillars were subsequently fabricated with a diameter of 2 μm within the same original β phase grain, and yield strength was measured using an in-situ mechanical compression device. The mechanical response of each micro-pillar was found to vary, and potential reasons for this phenomenon were discussed, including the impact of α-phase and β-dispersion on the material’s mechanical properties. Moreover, a clear size effect was observed when comparing the yield strength of the bulk material. Furthermore, the plastic deformation behavior of Ti-6Al-4V alloy was also investigated through compression tests on the micro-pillars.