Quantifying the effect of macrozones on the cold-dwell fatigue response of UD-Rolled Ti-6Al-4V using high-energy X-ray diffraction

Triantafyllou, C. , Pagan, D. C. and McBride, A. (2022) Quantifying the effect of macrozones on the cold-dwell fatigue response of UD-Rolled Ti-6Al-4V using high-energy X-ray diffraction. Materials Science and Engineering A: Structural Materials Properties Microstructure and Processing, 834, 142498. (doi: 10.1016/j.msea.2021.142498)

Abstract

High-energy X-ray diffraction is used to investigate the evolution of elastic lattice strains in rolled Ti-6Al-4V specimens during cyclic loading in-situ with and without the inclusion of a 120 s dwell period. A 1 mm segment of the gauge section is monitored throughout the first 100 cycles for specimens extracted along the rolling direction (RD), the transverse direction (TD) and 45° between the two, to explore the effects of texture on the evolution of the micromechanical response. Five families of lattice planes from the hexagonal phase are analysed with emphasis on lattice strain measured at the peak of each cycle, while macroscopic strain accumulation is simultaneously monitored via Digital Image Correlation. In cyclic loading conditions including a dwell period at load, a prominent increase in elastic strains is observed in prismatic and basal lattice planes with the specimen loaded from the rolling direction. In the absence of dwell, both RD and TD specimen orientations exhibited subtle cyclic hardening in all families of lattice planes probed despite negligible evolution in accumulated macroscopic plastic strain. Estimations of lattice orientation-dependent stresses are also presented using directional moduli to examine redistribution of load across sets of grains with the increasing cycle count.

• Item Type: Articles
• Additional Information: This research was carried out with the technical and financial support of Rolls-Royce plc and the EPSRC NPIF under award 1953429. This work is based upon research conducted at the Cornell High Energy Synchrotron Source (CHESS) under NSF award DMR-1332208 and the Center for High Energy X-ray Science (CHEXS) which is supported by NSF award DMR-1829070.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: McBride, Professor Andrew and Triantafyllou, Chris
• Authors: Triantafyllou, C., Pagan, D. C., and McBride, A.
• College/School: College of Science and Engineering; College of Science and Engineering > School of Engineering > Infrastructure and Environment
• Journal Name: Materials Science and Engineering A: Structural Materials Properties Microstructure and Processing
• Publisher: Elsevier
• ISSN: 0921-5093
• ISSN (Online): 1873-4936
• Published Online: 01 January 2022
• Copyright Holders: Copyright © 2022 Elsevier B.V
• First Published: First published in Materials Science and Engineering A: Structural Materials Properties Microstructure and Processing 834: 142498
• Publisher Policy: Reproduced in accordance with the publisher copyright policy

Project Code	Award No	Project Name	Principal Investigator	Funder's Name	Funder Ref	Lead Dept
304979		University of Glasgow NPIF 2018	Heather Lambie	Engineering and Physical Sciences Research Council (EPSRC)	EP/S515401/1	S&E - Graduate School