Measurements of residual stress and microstructural evolution in electron beam welded Ti-6Al-4V using multiple techniques

William Rae, Zak Lomas, Martin Jackson, Salah Rahimi

Research output: Contribution to journalArticle

13 Citations (Scopus)
15 Downloads (Pure)

Abstract

The evolution of residual stress and microstructure has been investigated in electron-beam welded Ti-6Al-4V alloy rings in order to develop an understanding of how the distribution of through-thickness residual stress correlates with microstructural evolution. A multiple technique approach to residual stress measurement was employed using a combination of different measurement techniques including X-ray diffraction (XRD), hole drilling method based on electronic speckle pattern interferometry (ESPI), and the contour method. It was found that there is a strong correlation between the change in residual stress and alpha phase morphology across the weld. The fusion zone exhibited highly tensile residual stress which was typified by an entirely acicular α′ microstructure formed by a displacive transformation within prior β grains on cooling. The tensile residual stress in the centre of the weld reduced towards the heat affected zone, transitioning to a compressive residual stress upon increasing distance from the weld centre. The transition from tensile to compressive residual stress correlates with a significant decrease in the volume fraction of α′ and an increase in the bimodal morphology of equiaxed primary alpha in a diffusional transformed beta matrix leading to elongated alpha in the base material.
Original languageEnglish
Pages (from-to)10-19
Number of pages10
JournalMaterials Characterization
Volume132
Early online date24 Jul 2017
DOIs
Publication statusPublished - 1 Oct 2017

Fingerprint

Microstructural evolution
residual stress
Electron beams
Residual stresses
electron beams
Welds
tensile stress
Compressive stress
Tensile stress
microstructure
Microstructure
heat affected zone
stress measurement
Stress measurement
speckle patterns
Heat affected zone
Speckle
drilling
Interferometry
Volume fraction

Keywords

  • X-ray diffraction
  • weld
  • residual stress
  • contour method
  • titanium alloy
  • phase transformation

Cite this

@article{a29e9dd30dd44dc9ad18f6955b58e43e,
title = "Measurements of residual stress and microstructural evolution in electron beam welded Ti-6Al-4V using multiple techniques",
abstract = "The evolution of residual stress and microstructure has been investigated in electron-beam welded Ti-6Al-4V alloy rings in order to develop an understanding of how the distribution of through-thickness residual stress correlates with microstructural evolution. A multiple technique approach to residual stress measurement was employed using a combination of different measurement techniques including X-ray diffraction (XRD), hole drilling method based on electronic speckle pattern interferometry (ESPI), and the contour method. It was found that there is a strong correlation between the change in residual stress and alpha phase morphology across the weld. The fusion zone exhibited highly tensile residual stress which was typified by an entirely acicular α′ microstructure formed by a displacive transformation within prior β grains on cooling. The tensile residual stress in the centre of the weld reduced towards the heat affected zone, transitioning to a compressive residual stress upon increasing distance from the weld centre. The transition from tensile to compressive residual stress correlates with a significant decrease in the volume fraction of α′ and an increase in the bimodal morphology of equiaxed primary alpha in a diffusional transformed beta matrix leading to elongated alpha in the base material.",
keywords = "X-ray diffraction, weld, residual stress, contour method, titanium alloy, phase transformation",
author = "William Rae and Zak Lomas and Martin Jackson and Salah Rahimi",
year = "2017",
month = "10",
day = "1",
doi = "10.1016/j.matchar.2017.07.042",
language = "English",
volume = "132",
pages = "10--19",
journal = "Materials Characterization",
issn = "1044-5803",

}

Measurements of residual stress and microstructural evolution in electron beam welded Ti-6Al-4V using multiple techniques. / Rae, William; Lomas, Zak; Jackson, Martin; Rahimi, Salah.

In: Materials Characterization, Vol. 132, 01.10.2017, p. 10-19.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Measurements of residual stress and microstructural evolution in electron beam welded Ti-6Al-4V using multiple techniques

AU - Rae, William

AU - Lomas, Zak

AU - Jackson, Martin

AU - Rahimi, Salah

PY - 2017/10/1

Y1 - 2017/10/1

N2 - The evolution of residual stress and microstructure has been investigated in electron-beam welded Ti-6Al-4V alloy rings in order to develop an understanding of how the distribution of through-thickness residual stress correlates with microstructural evolution. A multiple technique approach to residual stress measurement was employed using a combination of different measurement techniques including X-ray diffraction (XRD), hole drilling method based on electronic speckle pattern interferometry (ESPI), and the contour method. It was found that there is a strong correlation between the change in residual stress and alpha phase morphology across the weld. The fusion zone exhibited highly tensile residual stress which was typified by an entirely acicular α′ microstructure formed by a displacive transformation within prior β grains on cooling. The tensile residual stress in the centre of the weld reduced towards the heat affected zone, transitioning to a compressive residual stress upon increasing distance from the weld centre. The transition from tensile to compressive residual stress correlates with a significant decrease in the volume fraction of α′ and an increase in the bimodal morphology of equiaxed primary alpha in a diffusional transformed beta matrix leading to elongated alpha in the base material.

AB - The evolution of residual stress and microstructure has been investigated in electron-beam welded Ti-6Al-4V alloy rings in order to develop an understanding of how the distribution of through-thickness residual stress correlates with microstructural evolution. A multiple technique approach to residual stress measurement was employed using a combination of different measurement techniques including X-ray diffraction (XRD), hole drilling method based on electronic speckle pattern interferometry (ESPI), and the contour method. It was found that there is a strong correlation between the change in residual stress and alpha phase morphology across the weld. The fusion zone exhibited highly tensile residual stress which was typified by an entirely acicular α′ microstructure formed by a displacive transformation within prior β grains on cooling. The tensile residual stress in the centre of the weld reduced towards the heat affected zone, transitioning to a compressive residual stress upon increasing distance from the weld centre. The transition from tensile to compressive residual stress correlates with a significant decrease in the volume fraction of α′ and an increase in the bimodal morphology of equiaxed primary alpha in a diffusional transformed beta matrix leading to elongated alpha in the base material.

KW - X-ray diffraction

KW - weld

KW - residual stress

KW - contour method

KW - titanium alloy

KW - phase transformation

UR - http://www.sciencedirect.com/science/article/pii/S1044580317311397

U2 - 10.1016/j.matchar.2017.07.042

DO - 10.1016/j.matchar.2017.07.042

M3 - Article

VL - 132

SP - 10

EP - 19

JO - Materials Characterization

JF - Materials Characterization

SN - 1044-5803

ER -