Fusion Engineering and Design 85 (2010) 1469–1473
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Fusion Engineering and Design
journal homepage: www.elsevier.com/locate/fusengdes
Compatibility of atmospheric plasma sprayed Al
2
O
3
coatings on CLAM with
liquid LiPb
Zhihui Guo
a,∗
, Qunying Huang
a,b
, Zilin Yan
a
, Yong Song
a
, Zhiqiang Zhu
a
, Sheng Gao
a
, Qingsheng Wu
a
,
Chunjing Li
a
, Shaojun Liu
a
, Yongliang Wang
a
, Bo Huang
a
, Xuebin Zheng
c
, Yaran Niu
c
a
Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031, China
b
School of Nuclear Science and Technology, University of Science and Technology of China, Hefei, Anhui 230027, China
c
Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China
article info
Article history:
Available online 1 May 2010
Keywords:
Atmospheric plasma spray
Al2O3 coating
CLAM
LiPb
abstract
Aluminum oxide Al
2
O
3
coatings on China Low Activation Martensitic (CLAM) steel substrates were pre-
pared with atmospheric plasma spray (APS) method. Corrosion experiments of the coating specimens in
static liquid LiPb were carried out in DRAGON-ST capsule for 5000 h at 550
◦
C. The results showed that
there is no obvious thinning of external layer Al
2
O
3
after 5000 h exposure. The phase Al
2
O
3
in external
layer and the dissolution of Ni in liquid LiPb from the edge of the internal layer Ni–Cr were the possible
reasons for the corrosion of coatings.
Crown Copyright © 2010 Published by Elsevier B.V. All rights reserved.
1. Introduction
The liquid metal LiPb blanket design is one of the most promis-
ing designs for future fusion power reactors and under wide
research in the world. China, EU, USA, and other members of
International Thermonuclear Experimental Reactor (ITER) all pay
much attention to the R&D of the liquid LiPb blankets [1–3]. And
the liquid LiPb Test Blanket Module (TBM) design with Reduced
Activation Ferritic/Martensitic steel (RAFMs) as the structural
material becomes one of the most attractive designs for ITER TBM
[4,5].
However, some key issues still exist in LiPb blankets, such
as tritium permeation, corrosion of structural material and mag-
netohydrodynamics (MHD) effects, etc. [6–8]. One of the key
limitations of design and application of liquid metal coolant
systems in fusion reactors is the resistability of the available
structural materials to the corrosion of liquid metal. And it has
been recognized to be a serious problem in use of liquid metal
at high temperature systems which has been studied widely
since liquid metals were considered to be candidate materials
for the coolant of fusion reactors. A technology of great signif-
icance to solve the above problems is fabricating coatings on
the surface of the blanket materials. And aluminum oxide Al
2
O
3
∗
Corresponding author at: Institute of Plasma Physics, Reactor Technology Divi-
sion, Chinese Academy of Sciences, P.O. Box 1126, No. 350, Shushanhu Road, Hefei,
Anhui 230031, China. Tel.: +86 551 559 2424; fax: +86 551 559 3328.
E-mail address: zhguo@ipp.ac.cn (Z. Guo).
was proposed as a candidate material for ceramic coating in
the presence of LiPb because of its thermochemical stability in
LiPb, high electrical resistivity and radiation resistivity [9–12].
In this paper Al
2
O
3
coatings on China Low Activation Marten-
sitic (CLAM) steel substrates were prepared with atmospheric
plasma spray (APS) method. The coatings showed good adhe-
sion strength and electrical resistivity, and high microhardness
was also presented [13–15]. Therefore, further experiment and
study on the compatibility of coating with liquid LiPb was carried
out.
In order to study the compatibility of fusion materials with liq-
uid LiPb at different temperatures, a few facilities were designed
and fabricated in Institute of Plasma Physics, Chinese Academy of
Sciences, such as the thermal convection loop DRAGON-I, DRAGON-
II and the static isothermal capsule DRAGON-ST [16,17]. So far,
experiments on compatibility of different materials with liquid LiPb
have been carried out in these facilities for thousands of hours.
After the compatibility experiments, analyses by X-ray diffrac-
tion (XRD) test, scanning electron microscopy (SEM) observation
and energy dispersive X-ray (EDX) test for the specimens were car-
ried out to evaluate the compatibility of the above materials with
liquid LiPb.
2. Experimental procedures
2.1. Materials
The investigated materials were Al
2
O
3
coatings prepared
with APS method on specimens of CLAM (HEAT 0603B). Chem-
0920-3796/$ – see front matter. Crown Copyright © 2010 Published by Elsevier B.V. All rights reserved.
doi:10.1016/j.fusengdes.2010.04.007