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Title: In situ analysis of plasticity and damage nucleation in a Ti-6Al-4V alloy and laser weld

Journal Article · · Materials Characterization
; ; ; ;  [1]
  1. Univ Lyon, INSA Lyon, CNRS UMR5510, Laboratoire MATEIS, Villeurbanne Cedex, F-69621 (France)

Highlights: • EBSD in situ tensile test on a Ti-6Al-4V alloy and laser weld • Mainly prismatic, basal and pyramidal a slip activity in the base metal • Damage nucleation in the vicinity of the β phase and at α grain boundaries • Alignment of 10-10 crystallographic direction with the tensile axis in the α′ laths of the weld metal • Crack initiation along specific laths interfaces, former β grain boundary or twinned martensite laths in the weld metal The present work addresses the mechanisms of plasticity and damage nucleation in a Ti-6Al-4V alloy and its laser weld. To this end, in situ tensile tests are performed in a Scanning Electron Microscope (SEM) equipped with a Electron BackScatter Diffraction (EBSD) camera. The slip activity is automatically analyzed using a modified Schmid analysis. It is shown that the slip activity of the base metal consists mainly in prismatic, basal and pyramidal a slip. Damage nucleation in the vicinity of the β phase and at α grain boundaries is also evidenced in the base metal. In the α{sup ′} weld metal (a microstructure similar to the one often obtained in additive manufacturing Ti-alloy parts), plastic deformation results in a crystallographic rotation of the laths tending to align the 〈10 1-bar 0〉 direction with the tensile axis. The rare events of crack initiation in the martensite are shown to occur along specific laths interfaces, former β grain boundary or twinned martensite needles.

OSTI ID:
23112946
Journal Information:
Materials Characterization, Vol. 146; Other Information: Copyright (c) 2018 Elsevier Inc. All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 1044-5803
Country of Publication:
United States
Language:
English