Local strain rate sensitivity of α+β phases within dual-phase Ti alloys

Abstract

Using in-situ micropillar compression, the local strain rate sensitivity in Ti6242 and Ti6246 has been investigated to strengthen our understanding on the rate- and slip system-sensitive deformation of dual-phase Ti alloys. Electron backscatter diffraction (EBSD) was used to find target grains anticipating basal and primatic slip activities under compression test. Micropillars with similar α orientation and incomparable β morphology were made by a focused ion beam (FIB). Strain rate sensitivity (SRS) was determined based on the constant strain rate method (CSRM). The marked difference of SRS is found in the α+β of both alloys such that in Ti6242 the SRS in the basal slip is considerably higher than that in the prism whilst both slips in Ti6246 show somewhat similar SRS, inferring that either local chemical effects or the β morphology could affect rate-sensitive deformation behaviour.