<c + a> dislocations in deformed Ti–6Al–4V micro-cantilevers

Research output: Contribution to journalArticlepeer-review

Authors

Colleges, School and Institutes

Abstract

Single α–β colony micro-cantilevers with an equilateral triangular cross-section and an apex at the bottom were machined from a polycrystalline commercial Ti–6Al–4V sample using a focused ion beam (FIB). Each cantilever contained several α lamellae separated by thin fillets of β. A nano-indenter was used to perform micro-bending tests (Ding et al., 2012) [1]. 〈c + a〉 Slip systems were selectively activated in the cantilevers by controlling the crystal direction along the micro-cantilever to be [0 0 0 1]. Specimens for transmission electron microscopy were prepared from the deformed micro-cantilevers using a dual-beam FIB. Bright field scanning transmission electron microscopy was used to investigate the processes of slip nucleation, propagation and transmission through the α/β interface. Dislocations initiate first near the bottom of the cantilever and subsequently from the top. Both sets of dislocations move inward toward the neutral axis. Planar pyramidal View the MathML source slip was observed at the top (tension) but cross-slip was observed at the bottom (compression). All the 〈c + a〉 slip systems are equally stressed, but only a limited number is activated. This is tentatively interpreted in terms of dislocation transmission through the β fillets.

Details

Original languageEnglish
Pages (from-to)127-134
Number of pages8
JournalActa Materialia
Volume76
Early online date10 Jun 2014
Publication statusPublished - 1 Sep 2014

Keywords

  • 〈c + a〉 Dislocations, Micro-cantilever, Ti–6Al–4V