Observations on the post-mortem investigation of electron beam welds and other micro-structural features of JET Hypervapotrons

Mikael Brian Olsson Robbie, Niall Robert Hamilton, James Wood, Alexander Galloway, Joe Milnes, Ioannis Katramados

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

A metallurgical post-mortem investigation has been carried out on Mark 1 Hypervapotron elements from the Joint European Tokamak (JET), with the aim of aiding engineers in improving the future design of such high heat flux (HHF) component. Optical and electron microscopy and X-ray techniques have been utilised. Work has predominately focused on the electron beam (EB) welded and vacuum brazed joints of the Hypervapotron. Scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDX) has been used to assess the chemical composition while micro and nano indentation testing has been used to study the hardness profiles of these joints. Poor quality control of the vacuum brazing process resulted in nickel based filler material, contaminating internal surfaces. Variable penetration and entrapped voids in the EB welds suggested weld spiking occurred during the joining process. Details of these findings and a critical assessment of the potential implications are given where appropriate.
LanguageEnglish
Pages1642-1645
JournalFusion Engineering and Design
Volume86
Issue number9-11
Early online date3 Mar 2011
DOIs
Publication statusPublished - Oct 2011

Fingerprint

Electron beams
Welds
Vacuum brazing
Nanoindentation
Nickel
Joining
Electron microscopy
Optical microscopy
Quality control
Heat flux
Fillers
Hardness
Vacuum
Engineers
X rays
Scanning electron microscopy
Testing
Chemical analysis
X-Ray Emission Spectrometry

Keywords

  • hypervapotron
  • EB welding
  • vacuum brazing
  • metallurgy

Cite this

Olsson Robbie, Mikael Brian ; Hamilton, Niall Robert ; Wood, James ; Galloway, Alexander ; Milnes, Joe ; Katramados, Ioannis. / Observations on the post-mortem investigation of electron beam welds and other micro-structural features of JET Hypervapotrons. In: Fusion Engineering and Design. 2011 ; Vol. 86, No. 9-11. pp. 1642-1645.
@article{e5fc397d9b6a4b6996bf74323a47ecd0,
title = "Observations on the post-mortem investigation of electron beam welds and other micro-structural features of JET Hypervapotrons",
abstract = "A metallurgical post-mortem investigation has been carried out on Mark 1 Hypervapotron elements from the Joint European Tokamak (JET), with the aim of aiding engineers in improving the future design of such high heat flux (HHF) component. Optical and electron microscopy and X-ray techniques have been utilised. Work has predominately focused on the electron beam (EB) welded and vacuum brazed joints of the Hypervapotron. Scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDX) has been used to assess the chemical composition while micro and nano indentation testing has been used to study the hardness profiles of these joints. Poor quality control of the vacuum brazing process resulted in nickel based filler material, contaminating internal surfaces. Variable penetration and entrapped voids in the EB welds suggested weld spiking occurred during the joining process. Details of these findings and a critical assessment of the potential implications are given where appropriate.",
keywords = "hypervapotron , EB welding , vacuum brazing , metallurgy",
author = "{Olsson Robbie}, {Mikael Brian} and Hamilton, {Niall Robert} and James Wood and Alexander Galloway and Joe Milnes and Ioannis Katramados",
note = "Linked to Culham Centre for Fusion Energy",
year = "2011",
month = "10",
doi = "10.1016/j.fusengdes.2011.01.099",
language = "English",
volume = "86",
pages = "1642--1645",
journal = "Fusion Engineering and Design",
issn = "0920-3796",
number = "9-11",

}

Observations on the post-mortem investigation of electron beam welds and other micro-structural features of JET Hypervapotrons. / Olsson Robbie, Mikael Brian; Hamilton, Niall Robert; Wood, James; Galloway, Alexander; Milnes, Joe; Katramados, Ioannis.

In: Fusion Engineering and Design, Vol. 86, No. 9-11, 10.2011, p. 1642-1645.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Observations on the post-mortem investigation of electron beam welds and other micro-structural features of JET Hypervapotrons

AU - Olsson Robbie, Mikael Brian

AU - Hamilton, Niall Robert

AU - Wood, James

AU - Galloway, Alexander

AU - Milnes, Joe

AU - Katramados, Ioannis

N1 - Linked to Culham Centre for Fusion Energy

PY - 2011/10

Y1 - 2011/10

N2 - A metallurgical post-mortem investigation has been carried out on Mark 1 Hypervapotron elements from the Joint European Tokamak (JET), with the aim of aiding engineers in improving the future design of such high heat flux (HHF) component. Optical and electron microscopy and X-ray techniques have been utilised. Work has predominately focused on the electron beam (EB) welded and vacuum brazed joints of the Hypervapotron. Scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDX) has been used to assess the chemical composition while micro and nano indentation testing has been used to study the hardness profiles of these joints. Poor quality control of the vacuum brazing process resulted in nickel based filler material, contaminating internal surfaces. Variable penetration and entrapped voids in the EB welds suggested weld spiking occurred during the joining process. Details of these findings and a critical assessment of the potential implications are given where appropriate.

AB - A metallurgical post-mortem investigation has been carried out on Mark 1 Hypervapotron elements from the Joint European Tokamak (JET), with the aim of aiding engineers in improving the future design of such high heat flux (HHF) component. Optical and electron microscopy and X-ray techniques have been utilised. Work has predominately focused on the electron beam (EB) welded and vacuum brazed joints of the Hypervapotron. Scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDX) has been used to assess the chemical composition while micro and nano indentation testing has been used to study the hardness profiles of these joints. Poor quality control of the vacuum brazing process resulted in nickel based filler material, contaminating internal surfaces. Variable penetration and entrapped voids in the EB welds suggested weld spiking occurred during the joining process. Details of these findings and a critical assessment of the potential implications are given where appropriate.

KW - hypervapotron

KW - EB welding

KW - vacuum brazing

KW - metallurgy

UR - http://www.scopus.com/inward/record.url?scp=80054024301&partnerID=8YFLogxK

UR - http://www.sciencedirect.com/science/article/pii/S0920379611001116

U2 - 10.1016/j.fusengdes.2011.01.099

DO - 10.1016/j.fusengdes.2011.01.099

M3 - Article

VL - 86

SP - 1642

EP - 1645

JO - Fusion Engineering and Design

T2 - Fusion Engineering and Design

JF - Fusion Engineering and Design

SN - 0920-3796

IS - 9-11

ER -