% IMPORTANT: The following is UTF-8 encoded. This means that in the presence
% of non-ASCII characters, it will not work with BibTeX 0.99 or older.
% Instead, you should use an up-to-date BibTeX implementation like “bibtex8” or
% “biber”.
@ARTICLE{Raumann:894451,
author = {Raumann, L. and Coenen, J. W. and Riesch, J. and Mao, Y.
and Schwalenberg, D. and Wegener, T. and Gietl, H. and
Höschen, T. and Linsmeier, Ch. and Guillon, O.},
title = {{M}odeling and experimental validation of a {W} f
/{W}-fabrication by chemical vapor deposition and
infiltration},
journal = {Nuclear materials and energy},
volume = {28},
issn = {2352-1791},
address = {Amsterdam [u.a.]},
publisher = {Elsevier},
reportid = {FZJ-2021-03230},
pages = {101048},
year = {2021},
abstract = {Tungsten (W) has a unique combination of excellent thermal
properties, low sputter yield, low hydrogen retention, and
acceptable activation. Therefore, W is presently the main
candidate for the first wall material in future fusion
devices. However, its intrinsic brittleness and its further
embrittlement during operation bears the risk of a sudden
and catastrophic component failure. As a countermeasure,
tungsten fiber-reinforced tungsten (Wf/W) with extrinsic
toughening is being developed. A possible synthesis route is
chemical vapor deposition (CVD) using heated W fabrics as
substrate. The challenge is that the growing CVD-W can
isolate domains from precursor access leading to
strength-reducing pores. To deepen the process understanding
and to optimize the CVD parameters, models were developed
with COMSOL Multiphysics and validated experimentally. W
deposition rate equations as function of the temperature and
the partial pressures of the precursors H2 and WF6 were
experimentally validated in previous work. In the present
article, these equations are applied to obtain partial
pressures within the CVD reactor. The results are taken as
input for transient simulations in the microscale, in which
W coatings, growing onto multiple adjacent W fibers, were
simulated via mesh deformation and remeshing. The
surface-to-surface contact of the W coatings and the
corresponding potential pore formation were simulated by
implementing sophisticated deposition rate stop conditions.
Within the measuring uncertainties of $1\%,$ the models are
validated successfully by experimental comparison regarding
the deposition rate, pore structure, and relative densities
ranging from 0.6 to 0.9.},
cin = {IEK-4},
ddc = {624},
cid = {I:(DE-Juel1)IEK-4-20101013},
pnm = {1232 - Power-based Fuels and Chemicals (POF4-123) /
EUROfusion - Implementation of activities described in the
Roadmap to Fusion during Horizon 2020 through a Joint
programme of the members of the EUROfusion consortium
(633053)},
pid = {G:(DE-HGF)POF4-1232 / G:(EU-Grant)633053},
typ = {PUB:(DE-HGF)16},
UT = {WOS:000691545700003},
doi = {10.1016/j.nme.2021.101048},
url = {https://juser.fz-juelich.de/record/894451},
}