Surface morphology of Tungsten-F82H after high-heat flux testing using plasma-arc lamps

K. Ibano, A. S. Sabau, Kazutoshi Tokunaga, M. Akiyoshi, J. O. Kiggans, C. R. Schaich, Y. Katoh, Y. Ueda

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

F82H reduced activation steel coated with vacuum plasma sprayed (VPS) tungsten is a candidate as a plasma facing material for main chamber components in future fusion reactors. Due to different coefficients of thermal expansion (CTE), significant thermal stresses are expected in these bimetallic materials. Thus, a major uncertainty in the performance of W/F82H components during the operation under high-heat fluxes is the effect of CTE mismatch. In this study, a high intensity plasma-arc lamp was used for high-heat flux cycling tests of W/F82H specimens. While no surface damage was observed for specimens tested for 100–200 cycles at a heat flux of 1.4 MW/m2 pulse when the backside surface temperature was maintained below 550 °C, significant cracking occurred at higher temperatures. A simple analytical model for bimetallic materials indicated that the stress in the VPS-W layer is likely to exceed its failure stress solely due to the bilayer thermal stress. A finite element analysis of the state of stress and deformation confirmed that a significant stress also would occur at the W surface due to the rigid-body like constraint imposed by the clamp, which can be the main cause of the cracking.

Original languageEnglish
Pages (from-to)128-132
Number of pages5
JournalNuclear Materials and Energy
Volume16
DOIs
Publication statusPublished - Aug 1 2018

Fingerprint

Arc lamps
arc lamps
Tungsten
plasma jets
Surface morphology
Heat flux
heat flux
tungsten
Plasmas
Testing
thermal stresses
Thermal stress
Thermal expansion
thermal expansion
Vacuum
vacuum
cycles
clamps
fusion reactors
Steel

All Science Journal Classification (ASJC) codes

  • Nuclear and High Energy Physics
  • Materials Science (miscellaneous)
  • Nuclear Energy and Engineering

Cite this

Surface morphology of Tungsten-F82H after high-heat flux testing using plasma-arc lamps. / Ibano, K.; Sabau, A. S.; Tokunaga, Kazutoshi; Akiyoshi, M.; Kiggans, J. O.; Schaich, C. R.; Katoh, Y.; Ueda, Y.

In: Nuclear Materials and Energy, Vol. 16, 01.08.2018, p. 128-132.

Research output: Contribution to journalArticle

Ibano, K, Sabau, AS, Tokunaga, K, Akiyoshi, M, Kiggans, JO, Schaich, CR, Katoh, Y & Ueda, Y 2018, 'Surface morphology of Tungsten-F82H after high-heat flux testing using plasma-arc lamps', Nuclear Materials and Energy, vol. 16, pp. 128-132. https://doi.org/10.1016/j.nme.2018.06.015
Ibano, K. ; Sabau, A. S. ; Tokunaga, Kazutoshi ; Akiyoshi, M. ; Kiggans, J. O. ; Schaich, C. R. ; Katoh, Y. ; Ueda, Y. / Surface morphology of Tungsten-F82H after high-heat flux testing using plasma-arc lamps. In: Nuclear Materials and Energy. 2018 ; Vol. 16. pp. 128-132.
@article{1ea7a7b98c2640ad86a5a7b038e6817e,
title = "Surface morphology of Tungsten-F82H after high-heat flux testing using plasma-arc lamps",
abstract = "F82H reduced activation steel coated with vacuum plasma sprayed (VPS) tungsten is a candidate as a plasma facing material for main chamber components in future fusion reactors. Due to different coefficients of thermal expansion (CTE), significant thermal stresses are expected in these bimetallic materials. Thus, a major uncertainty in the performance of W/F82H components during the operation under high-heat fluxes is the effect of CTE mismatch. In this study, a high intensity plasma-arc lamp was used for high-heat flux cycling tests of W/F82H specimens. While no surface damage was observed for specimens tested for 100–200 cycles at a heat flux of 1.4 MW/m2 pulse when the backside surface temperature was maintained below 550 °C, significant cracking occurred at higher temperatures. A simple analytical model for bimetallic materials indicated that the stress in the VPS-W layer is likely to exceed its failure stress solely due to the bilayer thermal stress. A finite element analysis of the state of stress and deformation confirmed that a significant stress also would occur at the W surface due to the rigid-body like constraint imposed by the clamp, which can be the main cause of the cracking.",
author = "K. Ibano and Sabau, {A. S.} and Kazutoshi Tokunaga and M. Akiyoshi and Kiggans, {J. O.} and Schaich, {C. R.} and Y. Katoh and Y. Ueda",
year = "2018",
month = "8",
day = "1",
doi = "10.1016/j.nme.2018.06.015",
language = "English",
volume = "16",
pages = "128--132",
journal = "Nuclear Materials and Energy",
issn = "2352-1791",
publisher = "Elsevier Limited",

}

TY - JOUR

T1 - Surface morphology of Tungsten-F82H after high-heat flux testing using plasma-arc lamps

AU - Ibano, K.

AU - Sabau, A. S.

AU - Tokunaga, Kazutoshi

AU - Akiyoshi, M.

AU - Kiggans, J. O.

AU - Schaich, C. R.

AU - Katoh, Y.

AU - Ueda, Y.

PY - 2018/8/1

Y1 - 2018/8/1

N2 - F82H reduced activation steel coated with vacuum plasma sprayed (VPS) tungsten is a candidate as a plasma facing material for main chamber components in future fusion reactors. Due to different coefficients of thermal expansion (CTE), significant thermal stresses are expected in these bimetallic materials. Thus, a major uncertainty in the performance of W/F82H components during the operation under high-heat fluxes is the effect of CTE mismatch. In this study, a high intensity plasma-arc lamp was used for high-heat flux cycling tests of W/F82H specimens. While no surface damage was observed for specimens tested for 100–200 cycles at a heat flux of 1.4 MW/m2 pulse when the backside surface temperature was maintained below 550 °C, significant cracking occurred at higher temperatures. A simple analytical model for bimetallic materials indicated that the stress in the VPS-W layer is likely to exceed its failure stress solely due to the bilayer thermal stress. A finite element analysis of the state of stress and deformation confirmed that a significant stress also would occur at the W surface due to the rigid-body like constraint imposed by the clamp, which can be the main cause of the cracking.

AB - F82H reduced activation steel coated with vacuum plasma sprayed (VPS) tungsten is a candidate as a plasma facing material for main chamber components in future fusion reactors. Due to different coefficients of thermal expansion (CTE), significant thermal stresses are expected in these bimetallic materials. Thus, a major uncertainty in the performance of W/F82H components during the operation under high-heat fluxes is the effect of CTE mismatch. In this study, a high intensity plasma-arc lamp was used for high-heat flux cycling tests of W/F82H specimens. While no surface damage was observed for specimens tested for 100–200 cycles at a heat flux of 1.4 MW/m2 pulse when the backside surface temperature was maintained below 550 °C, significant cracking occurred at higher temperatures. A simple analytical model for bimetallic materials indicated that the stress in the VPS-W layer is likely to exceed its failure stress solely due to the bilayer thermal stress. A finite element analysis of the state of stress and deformation confirmed that a significant stress also would occur at the W surface due to the rigid-body like constraint imposed by the clamp, which can be the main cause of the cracking.

UR - http://www.scopus.com/inward/record.url?scp=85049340314&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85049340314&partnerID=8YFLogxK

U2 - 10.1016/j.nme.2018.06.015

DO - 10.1016/j.nme.2018.06.015

M3 - Article

AN - SCOPUS:85049340314

VL - 16

SP - 128

EP - 132

JO - Nuclear Materials and Energy

JF - Nuclear Materials and Energy

SN - 2352-1791

ER -