Ordering and the micromechanics of Ti-7Al
File(s)
Accepted version
Author(s)
Type
Journal Article
Abstract
The evolution of intergranular lattice strain in the α titanium alloy Ti–7Al wt% was characterised using in situ time-of-flight (TOF) neutron diffraction during room temperature tensile loading. Samples were aged to promote ordering and the formation of nanometre-scale α2 (Ti3Al). On ageing, at 550 °C and 625 °C, dislocations were observed to travel in pairs, and in planar arrays, which has been attributed to the presence of ordering. A slight change in c/a was observed, from 1.6949 to 1.6945, and a slight increase in the macroscopic modulus. However, no changes were observed in the residual lattice strains, which are the grain-orientation average elastic strains produced by plasticity. Therefore it is inferred that the changes in deformation mechanisms caused by ordering that result in an enhanced vulnerability to dwell fatigue affect primarily the extent of slip localisation. The overall strain distributions between grains in different orientations are not changed.
Date Issued
2015-09-21
Date Acceptance
2015-09-15
Citation
Materials Science and Engineering A: Structural Materials: Properties, Microstructure and Processing, 2015, 650, pp.28-37
ISSN
1873-4936
Publisher
Elsevier
Start Page
28
End Page
37
Journal / Book Title
Materials Science and Engineering A: Structural Materials: Properties, Microstructure and Processing
Volume
650
Copyright Statement
© 2015, Elsevier. Licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/
Sponsor
Engineering & Physical Science Research Council (EPSRC)
Engineering & Physical Science Research Council (EPSRC)
Rolls-Royce Plc
Grant Number
EP/H004882/1
EP/K034332/1
5002680312
Subjects
Science & Technology
Technology
Nanoscience & Nanotechnology
Materials Science, Multidisciplinary
Metallurgy & Metallurgical Engineering
Science & Technology - Other Topics
Materials Science
Titanium alloys
Neutron scattering
Ordering
ALPHA TITANIUM-ALLOY
SHORT-RANGE ORDER
TI-AL ALLOYS
PLASTIC-DEFORMATION
ROOM-TEMPERATURE
PRIMARY CREEP
PHASE
DIFFRACTION
FATIGUE
VULCAN
Publication Status
Published