Multiscale in situ deformation experiments: A sequential process from strain localization to failure in a laminated Ti-6Al-4V alloy

•Failure process of a Ti-6Al-4V alloy was studied by multi-scale in situ SEM.•Full scale strain mapping was carried out by sampling moiré method.•Cracking on grain boundaries with α-sheet was correlated with strain localization.•No relationship between interfacial strain localization and macroscopic shear localization.

The microscopic factors causing tensile failure of an α/β laminated Ti-6Al-4V alloy were investigated through in situ scanning electron microscopy and sampling moiré at an ambient temperature. Specifically, multiscale in situ microscopic observations were conducted to extract the most crucial factor of the failure. Slip localization in the vicinity of an intergranular α-sheet was clarified to be the primary factor that causes failure of the Ti-6Al-4V alloy. In addition, no relationship between interfacial strain localization and macroscopic shear localization at 45 degrees against the tensile direction was observed.