Comparative study of helium bubble formation in Cr-Fe-Ni-Mn high-entropy alloy and 18Cr10NiTi steel after irradiation and post-irradiation annealing
High entropy alloys (HEAs) are considered for applications in nuclear reactors due to their promising mechanical properties, corrosion and radiation resistance. In order to understand the irradiation effects in HEAs and to demonstrate their potential advantages over conventional austenitic stainless...
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| Cite this: | Comparative study of helium bubble formation in Cr-Fe-Ni-Mn high-entropy alloy and 18Cr10NiTi steel after irradiation and post-irradiation annealing / А.S. Kalchenko, S.A. Karpov, I.E. Kopanets, M.A. Tikhonovsky, G.D. Tolstolutskaya // Problems of atomic science and technology. — 2019. — № 5. — С. 25-29. — Бібліогр.: 20 назв. — англ. |
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Kalchenko, А.S. Karpov, S.A. Kopanets, I.E. Tikhonovsky, M.A. Tolstolutskaya, G.D. 2023-12-03T15:25:50Z 2023-12-03T15:25:50Z 2019 Comparative study of helium bubble formation in Cr-Fe-Ni-Mn high-entropy alloy and 18Cr10NiTi steel after irradiation and post-irradiation annealing / А.S. Kalchenko, S.A. Karpov, I.E. Kopanets, M.A. Tikhonovsky, G.D. Tolstolutskaya // Problems of atomic science and technology. — 2019. — № 5. — С. 25-29. — Бібліогр.: 20 назв. — англ. 1562-6016 PACS: 61.72.CC, 68.55. LN https://nasplib.isofts.kiev.ua/handle/123456789/195207 High entropy alloys (HEAs) are considered for applications in nuclear reactors due to their promising mechanical properties, corrosion and radiation resistance. In order to understand the irradiation effects in HEAs and to demonstrate their potential advantages over conventional austenitic stainless steels, we performed helium ion irradiation experiments with 20Cr-40Fe-20Ni-20Mn high-entropy alloy and 18Cr10NiTi steel under an identical condition. Both alloys have been irradiated to a dose of 4.8 displacement per atom (dpa) and a helium concentration of 11.7 at.% at room temperature. After subsequent annealing at 500°C the microstructure evolution of irradiated materials was examined. The irradiation promotes the formation of a high density of bubbles in HEA and steel. Comparison of parameters of helium porosity in these materials has been done. Високоентропійні сплави (ВЕС) розглядаються як перспективні матеріали для застосування в ядерних реакторах через їх багатообіцяючі механічні властивості, корозійну та радіаційну стійкість. З метою розуміння впливу опромінення на властивості ВЕС і демонстрації їх потенційних переваг у порівнянні зі звичайними аустенітними нержавіючими сталями ми провели експерименти з опромінення в ідентичних умовах іонами гелію з енергією 20 кеВ ВЕС 20Cr-40Fe-20Ni-20Mn і стали Х18Н10Т. Сплави були опромінені при кімнатній температурі до дози 4,8 зміщення на атом (зна) і концентрації гелію 11,7 ат.%. Еволюцію мікроструктури опромінених матеріалів досліджували після відпалу при 500°С. Опромінення і відпал призвели до створення високої щільності бульбашок у ВЕС і сталі. Проведено порівняння параметрів гелієвої пористості в цих матеріалах. Высокоэнтропийные сплавы (ВЭС) рассматриваются как перспективные материалы для применения в ядерных реакторах из-за их многообещающих механических свойств, коррозионной и радиационной стойкости. С целью понимания влияния облучения на свойства ВЭС и демонстрации их потенциальных преимуществ по сравнению с обычными аустенитными нержавеющими сталями мы провели эксперименты по облучению в идентичных условиях ионами гелия с энергией 20 кэВ ВЭС 20Cr-40Fe-20Ni-20Mn и стали Х18Н10Т. Оба сплава были облучены при комнатной температуре до дозы 4,8 смещения на атом (сна) и концентрации гелия 11,7 ат.%. Эволюцию микроструктуры облученных материалов исследовали после отжига при 500°С. Облучение и отжиг привели к образованию высокой плотности пузырьков в ВЭС и стали. Проведено сравнение параметров гелиевой пористости в этих материалах. en Національний науковий центр «Харківський фізико-технічний інститут» НАН України Вопросы атомной науки и техники Physics of radiation damages and effects in solids Comparative study of helium bubble formation in Cr-Fe-Ni-Mn high-entropy alloy and 18Cr10NiTi steel after irradiation and post-irradiation annealing Порівняльне дослідження розвитку гелієвих бульбашок у Cr-Fe-Ni-Mn високоентропійному сплаві і сталі Х18Н10Т після опромінення і пострадіаційного відпалу Сравнительное исследование развития гелиевых пузырьков в Cr-Fe-Ni-Mn высокоэнтропийном сплаве и стали Х18Н10Т после облучения и пострадиационного отжига Article published earlier |
| institution |
Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| collection |
DSpace DC |
| title |
Comparative study of helium bubble formation in Cr-Fe-Ni-Mn high-entropy alloy and 18Cr10NiTi steel after irradiation and post-irradiation annealing |
| spellingShingle |
Comparative study of helium bubble formation in Cr-Fe-Ni-Mn high-entropy alloy and 18Cr10NiTi steel after irradiation and post-irradiation annealing Kalchenko, А.S. Karpov, S.A. Kopanets, I.E. Tikhonovsky, M.A. Tolstolutskaya, G.D. Physics of radiation damages and effects in solids |
| title_short |
Comparative study of helium bubble formation in Cr-Fe-Ni-Mn high-entropy alloy and 18Cr10NiTi steel after irradiation and post-irradiation annealing |
| title_full |
Comparative study of helium bubble formation in Cr-Fe-Ni-Mn high-entropy alloy and 18Cr10NiTi steel after irradiation and post-irradiation annealing |
| title_fullStr |
Comparative study of helium bubble formation in Cr-Fe-Ni-Mn high-entropy alloy and 18Cr10NiTi steel after irradiation and post-irradiation annealing |
| title_full_unstemmed |
Comparative study of helium bubble formation in Cr-Fe-Ni-Mn high-entropy alloy and 18Cr10NiTi steel after irradiation and post-irradiation annealing |
| title_sort |
comparative study of helium bubble formation in cr-fe-ni-mn high-entropy alloy and 18cr10niti steel after irradiation and post-irradiation annealing |
| author |
Kalchenko, А.S. Karpov, S.A. Kopanets, I.E. Tikhonovsky, M.A. Tolstolutskaya, G.D. |
| author_facet |
Kalchenko, А.S. Karpov, S.A. Kopanets, I.E. Tikhonovsky, M.A. Tolstolutskaya, G.D. |
| topic |
Physics of radiation damages and effects in solids |
| topic_facet |
Physics of radiation damages and effects in solids |
| publishDate |
2019 |
| language |
English |
| container_title |
Вопросы атомной науки и техники |
| publisher |
Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
| format |
Article |
| title_alt |
Порівняльне дослідження розвитку гелієвих бульбашок у Cr-Fe-Ni-Mn високоентропійному сплаві і сталі Х18Н10Т після опромінення і пострадіаційного відпалу Сравнительное исследование развития гелиевых пузырьков в Cr-Fe-Ni-Mn высокоэнтропийном сплаве и стали Х18Н10Т после облучения и пострадиационного отжига |
| description |
High entropy alloys (HEAs) are considered for applications in nuclear reactors due to their promising mechanical properties, corrosion and radiation resistance. In order to understand the irradiation effects in HEAs and to demonstrate their potential advantages over conventional austenitic stainless steels, we performed helium ion irradiation experiments with 20Cr-40Fe-20Ni-20Mn high-entropy alloy and 18Cr10NiTi steel under an identical condition. Both alloys have been irradiated to a dose of 4.8 displacement per atom (dpa) and a helium concentration of 11.7 at.% at room temperature. After subsequent annealing at 500°C the microstructure evolution of irradiated materials was examined. The irradiation promotes the formation of a high density of bubbles in HEA and steel. Comparison of parameters of helium porosity in these materials has been done.
Високоентропійні сплави (ВЕС) розглядаються як перспективні матеріали для застосування в ядерних реакторах через їх багатообіцяючі механічні властивості, корозійну та радіаційну стійкість. З метою розуміння впливу опромінення на властивості ВЕС і демонстрації їх потенційних переваг у порівнянні зі звичайними аустенітними нержавіючими сталями ми провели експерименти з опромінення в ідентичних умовах іонами гелію з енергією 20 кеВ ВЕС 20Cr-40Fe-20Ni-20Mn і стали Х18Н10Т. Сплави були опромінені при кімнатній температурі до дози 4,8 зміщення на атом (зна) і концентрації гелію 11,7 ат.%. Еволюцію мікроструктури опромінених матеріалів досліджували після відпалу при 500°С. Опромінення і відпал призвели до створення високої щільності бульбашок у ВЕС і сталі. Проведено порівняння параметрів гелієвої пористості в цих матеріалах.
Высокоэнтропийные сплавы (ВЭС) рассматриваются как перспективные материалы для применения в ядерных реакторах из-за их многообещающих механических свойств, коррозионной и радиационной стойкости. С целью понимания влияния облучения на свойства ВЭС и демонстрации их потенциальных преимуществ по сравнению с обычными аустенитными нержавеющими сталями мы провели эксперименты по облучению в идентичных условиях ионами гелия с энергией 20 кэВ ВЭС 20Cr-40Fe-20Ni-20Mn и стали Х18Н10Т. Оба сплава были облучены при комнатной температуре до дозы 4,8 смещения на атом (сна) и концентрации гелия 11,7 ат.%. Эволюцию микроструктуры облученных материалов исследовали после отжига при 500°С. Облучение и отжиг привели к образованию высокой плотности пузырьков в ВЭС и стали. Проведено сравнение параметров гелиевой пористости в этих материалах.
|
| issn |
1562-6016 |
| url |
https://nasplib.isofts.kiev.ua/handle/123456789/195207 |
| citation_txt |
Comparative study of helium bubble formation in Cr-Fe-Ni-Mn high-entropy alloy and 18Cr10NiTi steel after irradiation and post-irradiation annealing / А.S. Kalchenko, S.A. Karpov, I.E. Kopanets, M.A. Tikhonovsky, G.D. Tolstolutskaya // Problems of atomic science and technology. — 2019. — № 5. — С. 25-29. — Бібліогр.: 20 назв. — англ. |
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| fulltext |
ISSN 1562-6016. PASТ. 2019. №5(123), p. 25-29.
COMPARATIVE STUDY OF HELIUM BUBBLE FORMATION
IN Cr-Fe-Ni-Mn HIGH-ENTROPY ALLOY AND 18Cr10NiTi STEEL
AFTER IRRADIATION AND POST-IRRADIATION ANNEALING
А.S. Kalchenko, S.A. Karpov, I.E. Kopanets, M.A. Tikhonovsky, G.D. Tolstolutskaya
National Science Center “Kharkov Institute of Physics and Technology”,
Kharkiv, Ukraine
E-mail: karpofff@kipt.kharkov.ua
High entropy alloys (HEAs) are considered for applications in nuclear reactors due to their promising
mechanical properties, corrosion and radiation resistance. In order to understand the irradiation effects in HEAs and
to demonstrate their potential advantages over conventional austenitic stainless steels, we performed helium ion
irradiation experiments with 20Cr-40Fe-20Ni-20Mn high-entropy alloy and 18Cr10NiTi steel under an identical
condition. Both alloys have been irradiated to a dose of 4.8 displacement per atom (dpa) and a helium concentration
of 11.7 at.% at room temperature. After subsequent annealing at 500 °C the microstructure evolution of irradiated
materials was examined. The irradiation promotes the formation of a high density of bubbles in HEA and steel.
Comparison of parameters of helium porosity in these materials has been done.
PACS: 61.72.CC, 68.55. LN
INTRODUCTION
A severe problem in the fission and fusion
irradiation environment is production of a certain
amount of transmutation elements through reactions of
(n, p) and (n, α) in the bulk of structural materials. The
high energy alpha particles can induce volume swelling
and high temperature He embrittlement by enhancing
the void nucleation and growth process due to low
solubility of helium in metals [1, 2].
The study of He-ions irradiation effects on materials,
including the formation and evolution of irradiation
damage defects and the diffusion and aggregation of
helium ions, has become one of the top challenges in
fusion field [3]. During migration of the vacancies and
helium atoms, the grain boundaries are more likely to be
the nucleation sites of helium bubble whose volume are
closely related to the irradiation temperature [2].
Very dense fine helium bubbles are formed at low
temperatures by continuously absorption of helium
atoms, while large bubbles are produced at high
temperatures. The increasing of the volume of helium
bubbles will lead to the blistering and the repeated
exfoliation of the sample surface, which will seriously
degrade the physical properties of materials and reduce
their service life [4].
A necessary task for develop new nuclear reactors
with safe, sustainable and efficient properties is the
research of structural materials with superior
performance in the extreme environment of high
temperature, high stress and intense irradiation damage.
Recently, in addition to traditional materials, a new
type of materials with excellent properties high
entropy alloys (HEAs) has been proposed [5]. HEAs are
defined as solid solution alloys that contain more than
four principal elements in equal or near equal atomic
percent (at.%), in which the high configurational
entropy of mixing reaches its maximum [6]. There are
also many other similar names, like multi-component
alloys, equiatomic ratio alloys and multi-principal-
elements alloys.
Extensive studies have revealed the excellent
properties of concentrated solid solution alloys,
including microstructure stability under ion irradiations,
a good corrosion resistance and the ability to maintain
good mechanical properties over a wide-range
temperature [7, 8]. However, the He behavior in HEAs,
including the formation and growth of He bubbles, is
still questionable.
In the present study, a non-cobalt 20Cr-40Fe-20 Ni-
20Mn (mass %) high entropy alloy has been
investigated. Cobalt is unfavorable element for nuclear
applications due to high neutron transmutation-induced
radioactivity.
The aim of this work is to study the microstructure
evolution of this material irradiated at room temperature
to a dose of 4.8 dpa and a helium concentration of
11.7 at.% and subsequently annealed at 500 °C.
Annealing was used as method for investigation of
exposure of the short-term high thermal flux on the first
wall material of fusion power reactor. Comparison of
the parameters of helium porosity in 20Cr-40Fe-20Ni-
20Mn and 18Cr10NiTi steel irradiated and annealed at
the same conditions was made.
EXPERIMENTAL DETAILS
High entropy alloy with the nominal compositions
(in mass %) of 20Cr-40Fe-20Mn-20Ni was produced by
arc melting in a high-purity argon in a water-cooled
copper mould. The purity of alloying elements was
above 99.9%. To ensure chemical homogeneity, the
ingots were flipped over and re-melted a least 5 times.
The alloy was studied after homogenization.
Homogenization annealing of ingots was carried out at
1050 °C and lasted for 24 h.
Alloys were subjected to thermomechanical
treatment (TMT) that consisted in deformation of the
rolling at room temperature from 6 mm to 0.2 mm with
intermediate annealing at 1100 °С for 3 h. Finishing
annealing after decreasing sample thickness to 0.2 mm
was carried out at 1100 °С for 1 h [9].
mailto:karpofff@kipt.kharkov.ua
18Cr10NiTi steel investigated in this study was
solution annealed at 1050 °С for 30 min.
Samples for TEM studies were prepared as disks of
3 mm in diameter. Thin foils were obtained by
mechanical thinning of the disks down to 130 µm
followed by electropolishing and short-term annealing.
The samples were implanted with 20 keV He
+
ions
to a dose of 110
21
m
-2
. Irradiations were performed with
irradiation facility in accelerating-measuring system
“ESU-2” [10]. The ion flux was 110
18
He/(m
2
·s). Ion
implantation was carried out at normal ion incidence.
The temperature of the sample did not exceed 25 °С
during irradiation.
The evolution of microstructure was investigated
after post-implantation annealing at 500 °С for 10 min.
Specimens were thinned for TEM examination by jet-
electropolishing with a solution of 5% perchloric acid
and 95% ethanol from back side of the sample until
perforation.
Ion stopping distribution for 20 keV helium ions and
irradiation damages (in dpa) have been calculated with
the software The Stopping and Range of Ions in Matter
(SRIM 2008) [11]. The dpa calculations are based on a
displacement energy threshold of 40 eV and on the
Kinchin-Pease formalism and Stoller recommendations
[12] (Fig. 1). The thickness of the foils was not
measured directly but assumed to be in the range of
100 nm according to their brightness in electron
microscope.
0 50 100 150 200
0
1
2
3
4
5
6
D
a
m
a
g
e
,
d
p
a
Depth, nm
0
2
4
6
8
10
12
14
C
o
n
c
e
n
tr
a
ti
o
n
,
a
t.
%
Fig. 1. Calculated profiles of damages and
concentrations of 20 keV He ions in 20Cr-40Fe-20Mn-
20Ni alloy irradiated to a dose of 1·10
21
m
-2
The microstructure of the alloys was studied by
electron microscope JEM-2100. Generally, small He
bubbles are observed at under-focused condition to
increase the imaging contrast. The average bubble size
was measured from more than 150 bubbles in each
sample.
RESULTS AND DISCUSSIONS
Fig. 2 shows typical initial microstructure of
18Cr10NiTi steel and 20Cr-40Fe-20Mn-20Ni high
entropy alloy.
The microstructure of unirradiated 18Cr10NiTi steel
consisted mostly of austenite grains (size ~ 30 µm), but
small crystallites of δ-ferrite were also observed at a
volume fraction of 2…3%. Annealing twins,
precipitates (carbides and titanium carbonitrides) and
dislocations (~ 10
8
cm
-2
) were seen in austenitic grains.
a
b
Fig. 2. The initial microstructure of 18Cr10NiTi
steel (a), 20Cr-40Fe-20Mn-20Ni high-entropy alloy (b)
The results of the study of the structure of HEA
alloy are described in [9]. According to X-ray analysis
as-cast alloy is single-phase with FCC crystal lattice.
After TMT and final heat treatment at 850 °C, the alloy
is single-phase also. Measured by means of EDS and
nominal compositions of HEA alloy and 18Cr10NiTi
steel are presented in Table 1.
Table 1
Nominal and measured materials composition (mass %)
Sample Fe Cr Ni Mn Ti Si
CrFeNiMn – – – – – –
Nominal 40 20 20 20 – –
Measured 41.23 19.82 19.42 19.18 – 0.35
18Cr10NiTi – – – – – –
Nominal Bal. 17-19 9-11 2 0.4-1 0.8
Measured 68.1 17.9 10.8 1.75 0.71 0.74
Fig. 3 shows the microstructure evolution of 20Cr-
40Fe-20Mn-20Ni high entropy alloy and 18Cr10NiTi
steel after He irradiation and subsequent annealing at
500 °C for 10 min in high vacuum. Irradiation leads to
the microstructural defects development, which induced
by nuclear collisions, as well as to the formation of
helium bubbles.
Detailed TEM characterization reveals that He
bubbles in 18 Cr10NiTi steel and Fe-Co-Cr-Ni alloy
exhibit different morphology and density.
The kinetics of helium porosity development at
annealing of 18Cr10NiTi stainless steel irradiated with
20 keV helium ions at room temperature have been
investigated in [13]. TEM examination of irradiated
steel was conducted in the annealing temperature range
from Troom to 1140 °C. At a dose of 1·10
21
m
-2
, bubbles
were observed immediately after irradiation at Troom. At
annealing, the average diameter of the bubbles varies
from ~ 2 nm at Troom to 10…20 nm at Tann = 1140 °C. In
the low-temperature region of annealing from Troom to
500 °C the average diameter and the density of bubbles
virtually does not change.
As shown in Fig. 3,a, in the case of 18Cr10NiTi,
very small and sparse spherical helium bubbles with
average diameter of ~ 1.6 nm and a density of
1.0·10
24
m
-3
have been observed.
In contrast, numerous bubbles with average
diameter of ≤ 1.0 nm were observed in irradiated Fe-Co-
Cr-Ni alloy (see Fig. 3,b). TEM observation was
conducted from over-focus to under-focus in several
samples. The bubble density and diameter in both
alloys, the uncertainties for the size and density are
summarized in Table 2.
a b
Fig. 3. The morphology and distribution of He bubbles in irradiated and subsequently annealed
18Cr10NiTi steel (a) and 20Cr-40Fe-20Mn-20Ni high entropy alloy (b)
Table 2
Helium bubbles size and density for 18Cr10NiTi steel and 20Cr-40Fe-20Mn-20Ni alloy
after irradiation and 500 °C annealing for 10 min
Sample
Helium
fluence, He
+
/m
2
Irradiation
damage, dpa
He concentration
at projected depth,
at. %
Mean
diameter,
nm
Number
density,
10
24
m
-3
Swelling,
%
FeCrNiMn 110
21
4.8 11.7 0.9±0.3 3.1±0.5 0.15
18Cr10NiTi 110
21
4.8 11.7 1.6±0.4 1.0±0.2 0.32
As can be seen from Table 1, the helium bubbles
size in CrFeNiMn alloy is smaller than that in
18Cr10NiTi steel, while the number density
approximately 3 times larger. Calculated values of
helium-associated swelling were evaluated to be 0.15
and 0.32% for HEA and 18Cr10NiTi, respectively,
suggesting that the helium bubble formation is
suppressed in the HEA. The suppression of bubble
formation may be related to the HEAs’ intrinsic
properties, i.e. severe large lattice distortion and
chemical disorder.
It is known that the extremely low solubility of
helium can exacerbate precipitation of He into clusters
or bubbles at sinks which causes property degradation
of structural materials. However, the different bubble
behavior between studied materials is observed.
Yan et al. [14] have demonstrated that high
temperature annealing leads to a formation of large
bubbles and cavities (hundreds of nanometers) in Ni,
while in Fe-Co-Cr-Ni bubble growth was limited.
Authors explained these observations by low helium
diffusivity in Fe-Co-Cr-Ni that results in suppression of
helium bubbles nucleation and growth (Fig. 4).
Fig. 4. Schematic diagram of the fluctuation of lattice
potential energy in Fe-Co-Cr-Ni alloy and pure nickel.
EI
M
and EV
B
are migration energy of interstitial He and
binding energy between He atom and vacancy,
respectively 13
As follows from Fig. 4, interstitial migration is
strongly controlled by the migration energy of
interstitial He, EI
M
, since He atoms can migrate via
jumps between different interstitial positions [14].
In the case of vacancy migration mechanism, the
binding energy between He atom and vacancy, EV
B
, will
primarily govern migration process.
Helium atoms injected into the lattice upon
irradiation migrate through interstitial positions before
trapping and agglomerating with vacancies (see Fig. 4).
Tsai et al. [8, 15] have studied kinetics of diffusion
of Co, Cr, Fe, Mn, and Ni in high entropy alloy by using
the method of diffusion couple. They founded that the
diffusion coefficients are lower in HEA compared to
conventional metals. Large fluctuations of lattice
potential energy in Co-Cr-Fe-Mn-Ni facilitate the
formation of deeper traps and atomic blocks resulted in
high activation energy and low diffusion mobility of
atoms.
Despite a discrepancy between regular atomic
diffusion and interstitial He diffusion due to its low
solubility and ability to form bubbles, the effect of
sluggish diffusion can be used to explain the differences
in the behavior of He in Fe-Co-Cr-Ni equiatomic alloy
and steel.
It was suggested in [14] that due to the considerable
lattice distortion, the potential energy gap between two
adjacent positions in the Fe-Co-Cr-Ni lattice is rather
large relative to the ideal zero in pure nickel, as injected
He atoms in Fe-Co-Cr-Ni are influenced by severe
fluctuations in the lattice potential energy during
frequent jumps in the process of diffusion and the
formation of clusters. As a result, a larger number of
helium atoms may be captured by traps with low
potential energy (shown by the blue arrow in Fig. 4).
Due to difficult migration of He atoms, the formation of
helium bubbles is retarded in HEA, wherefore Fe-Co-
Cr-Ni has a much higher critical He concentration
needed to detect TEM-visible helium bubbles at room
temperature.
Frenkel pairs will be generated in a cascade of
defects due to ion irradiation of both CrFeMnNi HEA
and steel. As has been demonstrated in [16], upon the
cooling down of the ballistic phase (0.5 picosecond) of
the damage cascade, defect recombination will take
place during the kinetic phase within a picosecond. The
number of defects that will survive in this case is ≈ 30%
for metals [17, 18]. The processes of generation and
recombination of defects caused by irradiation have a
nanosecond time scale [19], while sluggish diffusion
and evolution of defects may continue microseconds in
HEAs [20].
Y.N. Osetsky et al. [20] believe that the physical
origin of the sluggish diffusion effect may be attributed
to the compositional dependence of vacancy migration
energy with maximum near the site percolation
threshold, and argued that the coupled percolation and
composition-dependent barriers for vacancy jumps
within different subsystems in HEA leads to the
sluggish diffusion.
Implanted helium atoms located in interstitial
positions will ultimately recombine with surviving
defects, leading to the bubble’s nucleation throughout
the irradiated layer. The lower helium swelling in HEA
compared to steel, observed in this study, indicates that
the mechanism of inert gas bubble growth in HEA can
be suppressed.
CONCLUSION
The microstructure evolution in Cr-Fe-Ni-Mn high-
entropy alloy and 18Cr10NiTi stainless steel after
irradiation with helium ions to 4.8 dpa and 11.7 at.% at
room temperature and post-irradiation annealing was
investigated.
Irradiation promoted the formation of a high density
of bubbles in HEA and steel. Comparison of the
parameters of helium porosity in these materials showed
that the swelling in CrFeNiMn alloy is about two times
smaller than that in 18Cr10NiTi steel.
The obtained result indicates that CrFeNiMn is
much more resistant to the formation of helium bubbles
than conventional 18Cr10NiTi stainless steel.
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Article received 15.08.2019
СРАВНИТЕЛЬНОЕ ИССЛЕДОВАНИЕ РАЗВИТИЯ ГЕЛИЕВЫХ ПУЗЫРЬКОВ
В Cr-Fe-Ni-Mn ВЫСОКОЭНТРОПИЙНОМ СПЛАВЕ И СТАЛИ Х18Н10Т
ПОСЛЕ ОБЛУЧЕНИЯ И ПОСТРАДИАЦИОННОГО ОТЖИГА
А.С. Кальченко, С.А. Карпов, И.Е. Копанец, М.А. Тихоновский, Г.Д. Толстолуцкая
Высокоэнтропийные сплавы (ВЭС) рассматриваются как перспективные материалы для применения в
ядерных реакторах из-за их многообещающих механических свойств, коррозионной и радиационной
стойкости. С целью понимания влияния облучения на свойства ВЭС и демонстрации их потенциальных
преимуществ по сравнению с обычными аустенитными нержавеющими сталями мы провели эксперименты
по облучению в идентичных условиях ионами гелия с энергией 20 кэВ ВЭС 20Cr-40Fe-20Ni-20Mn и стали
Х18Н10Т. Оба сплава были облучены при комнатной температуре до дозы 4,8 смещения на атом (сна) и
концентрации гелия 11,7 ат.%. Эволюцию микроструктуры облученных материалов исследовали после
отжига при 500 °С. Облучение и отжиг привели к образованию высокой плотности пузырьков в ВЭС и
стали. Проведено сравнение параметров гелиевой пористости в этих материалах.
ПОРІВНЯЛЬНЕ ДОСЛІДЖЕННЯ РОЗВИТКУ ГЕЛІЄВИХ БУЛЬБАШОК
У Cr-Fe-Ni-Mn ВИСОКОЕНТРОПІЙНОМУ СПЛАВІ І СТАЛІ Х18Н10Т
ПІСЛЯ ОПРОМІНЕННЯ І ПОСТРАДІАЦІЙНОГО ВІДПАЛУ
О.С. Кальченко, С.О. Карпов, І.Є. Копанець, М.А. Тихоновський, Г.Д. Толстолуцька
Високоентропійні сплави (ВЕС) розглядаються як перспективні матеріали для застосування в ядерних
реакторах через їх багатообіцяючі механічні властивості, корозійну та радіаційну стійкість. З метою
розуміння впливу опромінення на властивості ВЕС і демонстрації їх потенційних переваг у порівнянні зі
звичайними аустенітними нержавіючими сталями ми провели експерименти з опромінення в ідентичних
умовах іонами гелію з енергією 20 кеВ ВЕС 20Cr-40Fe-20Ni-20Mn і стали Х18Н10Т. Сплави були
опромінені при кімнатній температурі до дози 4,8 зміщення на атом (зна) і концентрації гелію 11,7 ат.%.
Еволюцію мікроструктури опромінених матеріалів досліджували після відпалу при 500 °С. Опромінення і
відпал призвели до створення високої щільності бульбашок у ВЕС і сталі. Проведено порівняння параметрів
гелієвої пористості в цих матеріалах.
http://www.srim.org/
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