Superplastic deformation of the AK4-1 alloy with a surface layer melted by electron pulse beam
Specimens of the aluminum alloy AK4-1, previously irradiated by a pulsed electron beam, are deformed under the conditions of superplasticity. The features of structural changes in the course of superplastic deformation of preirradiated specimens are studied. It is shown that the deformation processe...
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Національний науковий центр «Харківський фізико-технічний інститут» НАН України
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| Цитувати: | Superplastic deformation of the AK4-1 alloy with a surface layer melted by electron pulse beam / V.V. Bryukhovetsky, A.V. Poyda, V.P. Poyda, D.E. Milaya // Problems of atomic science and technology. — 2019. — № 2. — С. 67-73. — Бібліогр.: 24 назв. — англ. |
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Bryukhovetsky, V.V. Poyda, A.V. Poyda, V.P. Milaya, D.E. 2023-12-01T16:07:52Z 2023-12-01T16:07:52Z 2019 Superplastic deformation of the AK4-1 alloy with a surface layer melted by electron pulse beam / V.V. Bryukhovetsky, A.V. Poyda, V.P. Poyda, D.E. Milaya // Problems of atomic science and technology. — 2019. — № 2. — С. 67-73. — Бібліогр.: 24 назв. — англ. 1562-6016 https://nasplib.isofts.kiev.ua/handle/123456789/194930 539.374+669.715 Specimens of the aluminum alloy AK4-1, previously irradiated by a pulsed electron beam, are deformed under the conditions of superplasticity. The features of structural changes in the course of superplastic deformation of preirradiated specimens are studied. It is shown that the deformation processes occurring in the main part of the specimen and in the layer, melted by a pulsed electron beam, have fundamental differences. Зразки алюмінієвого сплаву АК4-1, попередньо опромінені імпульсним пучком електронів, були продеформовані в умовах надпластичності. Вивчено особливості структурних змін у ході надпластичної деформації попередньо опромінених зразків. Показано, що деформаційні процеси, що відбуваються в основній частині зразка і в переплавленому імпульсним пучком електронів шарі, мають принципові відмінності. Образцы алюминиевого сплава АК4-1, предварительно облученные импульсным пучком электронов, были продеформированы в условиях сверхпластичности. Изучены особенности структурных изменений в ходе сверхпластической деформации предварительно облученных образцов. Показано, что деформационные процессы, происходящие в основной части образца и в переплавленном импульсным пучком электронов слое, имеют принципиальные различия. en Національний науковий центр «Харківський фізико-технічний інститут» НАН України Вопросы атомной науки и техники Physics of radiation damages and effects in solids Superplastic deformation of the AK4-1 alloy with a surface layer melted by electron pulse beam Надпластична деформація сплаву АК4-1 з поверхневим шаром, переплавленим імпульсним пучком електронів Сверхпластическая деформация сплава АК4-1 с поверхностным слоем, переплавленным импульсным пучком электронов Article published earlier |
| institution |
Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| collection |
DSpace DC |
| title |
Superplastic deformation of the AK4-1 alloy with a surface layer melted by electron pulse beam |
| spellingShingle |
Superplastic deformation of the AK4-1 alloy with a surface layer melted by electron pulse beam Bryukhovetsky, V.V. Poyda, A.V. Poyda, V.P. Milaya, D.E. Physics of radiation damages and effects in solids |
| title_short |
Superplastic deformation of the AK4-1 alloy with a surface layer melted by electron pulse beam |
| title_full |
Superplastic deformation of the AK4-1 alloy with a surface layer melted by electron pulse beam |
| title_fullStr |
Superplastic deformation of the AK4-1 alloy with a surface layer melted by electron pulse beam |
| title_full_unstemmed |
Superplastic deformation of the AK4-1 alloy with a surface layer melted by electron pulse beam |
| title_sort |
superplastic deformation of the ak4-1 alloy with a surface layer melted by electron pulse beam |
| author |
Bryukhovetsky, V.V. Poyda, A.V. Poyda, V.P. Milaya, D.E. |
| author_facet |
Bryukhovetsky, V.V. Poyda, A.V. Poyda, V.P. Milaya, D.E. |
| 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 |
Надпластична деформація сплаву АК4-1 з поверхневим шаром, переплавленим імпульсним пучком електронів Сверхпластическая деформация сплава АК4-1 с поверхностным слоем, переплавленным импульсным пучком электронов |
| description |
Specimens of the aluminum alloy AK4-1, previously irradiated by a pulsed electron beam, are deformed under the conditions of superplasticity. The features of structural changes in the course of superplastic deformation of preirradiated specimens are studied. It is shown that the deformation processes occurring in the main part of the specimen and in the layer, melted by a pulsed electron beam, have fundamental differences.
Зразки алюмінієвого сплаву АК4-1, попередньо опромінені імпульсним пучком електронів, були продеформовані в умовах надпластичності. Вивчено особливості структурних змін у ході надпластичної деформації попередньо опромінених зразків. Показано, що деформаційні процеси, що відбуваються в основній частині зразка і в переплавленому імпульсним пучком електронів шарі, мають принципові відмінності.
Образцы алюминиевого сплава АК4-1, предварительно облученные импульсным пучком электронов, были продеформированы в условиях сверхпластичности. Изучены особенности структурных изменений в ходе сверхпластической деформации предварительно облученных образцов. Показано, что деформационные процессы, происходящие в основной части образца и в переплавленном импульсным пучком электронов слое, имеют принципиальные различия.
|
| issn |
1562-6016 |
| url |
https://nasplib.isofts.kiev.ua/handle/123456789/194930 |
| citation_txt |
Superplastic deformation of the AK4-1 alloy with a surface layer melted by electron pulse beam / V.V. Bryukhovetsky, A.V. Poyda, V.P. Poyda, D.E. Milaya // Problems of atomic science and technology. — 2019. — № 2. — С. 67-73. — Бібліогр.: 24 назв. — англ. |
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2025-11-26T21:56:36Z |
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ISSN 1562-6016. PASТ. 2019. №2(120), p. 67-73.
UDС 539.374+669.715
SUPERPLASTIC DEFORMATION OF THE AK4-1 ALLOY WITH A
SURFACE LAYER MELTED BY ELECTRON PULSE BEAM
V.V. Bryukhovetsky
1
, A.V. Poyda
1
, V.P. Poyda
2
, D.E. Milaya
1,2
1
Institute of Electrophysics and Radiating Technologies NAS of Ukraine, Kharkov, Ukraine
E-mail: ntcefo@yahoo.com;
2
V.N. Karazin Kharkiv National University, Kharkov, Ukraine
E-mail: postmaster@univer.kharkov.ua
Specimens of the aluminum alloy AK4-1, previously irradiated by a pulsed electron beam, are deformed under
the conditions of superplasticity. The features of structural changes in the course of superplastic deformation of pre-
irradiated specimens are studied. It is shown that the deformation processes occurring in the main part of the
specimen and in the layer, melted by a pulsed electron beam, have fundamental differences.
INTRODUCTION
The vast majority of modern constructional and tool
materials are produced with hardened working surfaces
or applied coatings. The properties of the surface metal
interlayers very often play a decisive role in maintaining
the performance characteristics of the alloys in terms of
their use as structural materials and parts of
mechanisms. However, increasing, thus, the operational
resource of materials significantly reduces their
plasticity, since stress concentrators arise at the
interfaces between materials. The failure of the material
most often begins from the surface. Therefore, the study
of the deformational mechanisms of materials with
reinforcing coatings or surface-hardened layers is of
great practical and scientific interest.
In the case of constructional aluminum alloys,
special surface layers forms as a result of their hot
rolling. Also, as a special surface layer may be the
presence of a cladding layer of technically pure
aluminum. One of the promising methods of modifying
the surface of materials is electrophysical radiation
processing. Processing by a pulsed beam of relativistic
electrons leads to a change in the physical and chemical
properties of the surface layer of the material, which is
often used to obtain hardening and protective coatings
[1]. The structure and properties of the thus obtained
layers were previously studied in a number of papers [2–
5]. In this work, specimens of heat-resistant industrial
aluminum alloy AK4-1 were subjected to this kind of
irradiation.
From the point of view of physical mesomechanics,
the deformation processes in the surface layers and the
volume of the material develop, although correlated, but
autonomously at all stages [6]. At the same time, it is
analytically shown in [7] that the coating of a low-
plastic metal by a layer with high plastic properties leads
to an increase in the plasticity of such a composite.
Proper understanding of the behavior of the surface
layers of material during superplastic deformation is
important when developing technologies for deforming
materials under superplasticity conditions. Various
aspects of the behavior of surface layers during
superplastic deformation have already been investigated
previously in a number of works [8–10]. In this work,
we studied behavior of the surface layer of specimens of
heat-resistant aluminum alloy AK4-1 under the
conditions of superplastic deformation. In this case, the
surface layer in this alloy was created by irradiating of
the specimens by a pulsed electron beam. Such studies
are very important both for a deeper understanding of
the physical nature of the superplasticity effect, and for
the possibility of applying technologies of superplastic
forming to materials whose surface is processed by
pulsed energy action.
1. MATERIAL AND EXPERIMENTAL
Alloy AK4-1 (another designation – alloy 1141) has
the following chemical composition: Al;
2.0…2.6 wt.% Cu; 1.2…1.8 wt.% Mg; 0.9…1.4 wt.% Fe;
0.9…1.4 wt.% Ni; 0.1…0.25 wt.% Si; 0.05…0.1 wt.% Ti;
0.1 wt.% Mn; 0.1 wt.% Zn [11]. This alloy is one of the
deformable by pressure alloys and is widely used in
mechanical engineering and aircraft construction. Due to
the presence of iron and nickel in the composition of the
alloy AK4-1, this alloy is also heat resistant. Irradiation
of alloys’ plates were performed by a high-current
pulsed beam of relativistic electrons at the MIG-1
accelerator in the NSC KIPT NAS of Ukraine [1]. The
energy flux density at the target W is approximately
109 W/cm
2
(beam energy E ~ 0.3 MeV, current
I ~ 2000 A, pulse duration τi ~ 5·10
-6
s, beam diameter
D ~ 3 cm).
The prismatic specimens cut from the industrial
semi-finished product of the alloy AK4-1 along the
rolling direction had the following working section
dimensions: 2.04.510 mm. Mechanical tensile tests of
the specimens were performed in air in creep mode at a
constant flow stress. Creep curves were recorded
automatically using the electronic recorder EPP-09.
They were rebuilt in the coordinates of the true
deformation – time. The true strain rate was
determined from creep curves.
Structural studies at various stages of specimens’
deformation were carried out using light (MIM-6) and
scanning electron microscopy (JEOL JSM-840).
The kinetics of phase transformations occurring in
specimens of АК4-1 alloy in the process of heating was
investigated on a Derivatograph Q-1550 device.
mailto:ntcefo@yahoo.com
mailto:postmaster@univer.kharkov.ua
2. RESULTS AND DISCUSSION
Processing of the products by concentrated energy
flows makes it possible to purposefully modify the
properties of the surface layers. The use of high-current
relativistic electron beams with a power density of up to
10
9
W/cm
2
for this purpose allows to heat and melt the
surface layer to a depth of 100 μm quickly and
uniformly over a relatively large area [1]. The impact of
the electron beam is combined: percussive, thermal and
radiational [1–6]. The rapid solidification of the molten
layer under the conditions of large temperature gradient
and high pressures leads to directional solidification of
the melt under non-equilibrium conditions, obtaining
nanocrystalline and amorphous structures, redistributing
the alloying components of the alloy in the melted layer
[2–5]. All this leads to a change in the properties of the
near-surface layer.
Fig. 1,a shows a general view of a plate surface made
from an AK4-1 alloy sheet, which was irradiated by a
pulsed electron beam. It can be seen that the intense
heating of the plate produced by the electron beam led
to the melting of its surface layer. A general view of the
AK4-1 alloy specimen for mechanical testing, which
was cut from irradiated plate, is also shown in Fig. 1,a.
Fig. 1,b shows the characteristic surface relief of the
plates after irradiation. It is seen that the intense heating
generated by the action of an electron beam leads to the
melting of the surface layer. The thickness of the
remelted layer, as can be seen from Fig. 1,c is about
100 m. The presence of long cracks, which are
branched, indicates the presence of significant internal
stresses, which arise in the melted layer at the moment
of solidification on the surface (see Fig. 1,b). As can be
seen from Fig. 1,c, the cracks spread to the entire depth
of the melted layer. Zigzag crack propagation is
probably related to the local heterogeneity of the
strength and plastic properties of the material in various
microvolumes and, in particular, to the local
heterogeneity of the distribution of alloying elements in
the solidified material or local heterogeneity of the
distribution in the near-surface zone of particles of
intermetallic phases. Apparently, the relaxation of
internal stresses resulting from exposure by radiation on
the surface of AK4-1 alloy plate was not fully realized
during the crystallization of the melted surface layer,
therefore, the remaining internal stresses caused the
formation of cracks.
Mechanical tests of initial non-irradiated specimens
of this alloy AK4-1 in creep mode at a constant applied
flow stress were performed earlier in [12]. Tests were
performed at temperatures of 753, 773, 793, 813 K and
a range of flow stresses = 4.0…8.0 MPa. The
specimens of AK4-1 alloy showed the effect of
superplasticity at test temperatures of 773, 793, 813 K.
Therefore, the mechanical tests of the irradiated
specimens were performed at these three temperatures.
Fig. 2 shows the graphs of the dependences of
elongation to failure δ from the applied flow stress σ for
irradiated specimens of alloy AK4-1, deformed to
failure at temperatures 773, 793, 813 К. It can be seen
that the dependences of the relative elongation to failure
δ of irradiated specimens of alloy AK4-1 from the
applied flow stress σ at these test temperatures has a
typical for superplasticity view of curves with
maximum.
Fig. 1. A general view of the plate surface made from
AK4-1 alloy irradiated by a pulsed electron beam and a
specimen cut from it for mechanical testing (a);
the characteristic view of the surface fragment of the
working part of the alloy AK4-1 specimens (b);
microstructure of the alloy AK4-1 in the electron beam
processing zone (c)
The results of mechanical tests of irradiated
specimens are practically identical with those of the
unirradiated specimens performed in [9]. Structural
studies, which were performed in [12], led to the
conclusion about the implementation of grain boundary
sliding under the conditions of superplastic deformation
of alloy AK4-1 specimens. The development of this
process, in particular, is evidenced by the identification
of a developed deformation relief on the previously
polished smooth surface of the working part of
specimens.
Fig. 2. Dependencies δ = f (σ) for specimens of alloy
AK4-1, deformed to failure at:
T = 773 K (curve 1); T = 793 K (curve 2);
T = 813 K (curve 3)
Also during deformation of the alloy AK4-1
specimens, the formation of grain-boundary cavities and
cracks, as well as breaks in previously applied reference
marks, was observed.
Superplastic deformation of the material at elevated
temperatures can be described by the following equation
[13]:
p n
ADGb b
kT d G
, (1)
where is strain rate; A is a constant relevant to
deformation mechanism; G is the shear modulus; T is
the absolute temperature; k = 1.38·10
-23
J/K is
Boltzmann’s constant; b is the Burgers vector; d is the
grain size; p is the grain size exponent (p = 0 for
dislocation creep, p = 2 for lattice diffusion as the rate
controlling mechanism, p = 3 for grain boundary
controlled flow); n (= 1/m) is the stress exponent; D is
the appropriate diffusion coefficient. The diffusion
coefficient D is defined as D = D0exp(-Q/RT), where D0
is the preexponent, Q is the diffusion activation energy
and R = 8.314 J∙mol
-1
·K
-1
is the gas constant.
According to Eq. (1), the strain rate sensitivity
exponents, m, can be defined as
σ
ε
dln
m
dln
, (2)
Fig. 3 shows variation of flow stress at a true strain
of 0.2 as a function of strain rate at different
temperatures. The m values vary from 0.35 to 0.53,
indicating that the superplastic mechanism could be a
combination of dislocation viscous glide and GBS. The
maximum elongation of 230% is achieved at 793 К with
strain rate of 3.110
-4
s
-1
, corresponding to the maximum
m-value of 0.53, which implies that GBS becomes the
predominant mechanism of deformation.
Fig. 4 shows a series of images of the working part
surface of the alloy AK4-1 specimen. The specimen was
pre-irradiated by a pulsed electron beam, and then
deformed superplastically to various degrees of
deformation. It can be seen that the state of the surface
remelted layer after deformation under superplastic
conditions differs from the general state of the deformed
specimen.
Fig. 3. Dependencies lgσ = f (lg ) for specimens of
alloy AK4-1 deformed at:
T = 773 K (curve 1); T = 793 K (curve 2);
T = 813 K (curve 3)
The melted layer has multiple fractures and
delaminations. Apparently, the fragments of this layer
sided along the surface of the part of the specimen that
was not melted by the electron beam. That is, the
deformation processes occurring in the main part of the
specimen and in the layer remelted by a pulsed electron
beam are fundamentally different. While the main part
of the specimen, considering the data of mechanical
tests, deforms superplastically, the surface remelted
layer is divided into the nucleated fragments. This is
confirmed by a general view of fracture fractogram of
deformed irradiated specimen (Fig. 5). According to the
fracture fractogram, it can be seen that the thickness of
the specimen during the deformation process decreased
almost three times. At the same time, the upper modified
layer formed as a result of irradiation practically does
not decrease in thickness over the time of deformation.
Its thickness remained about 100 m. It, being divided
into fragments, is dispersed on the surface of the
deformable part of the specimen. Apparently, only the
main non-melted part of the specimen flows
superplastically.
As can be seen from Fig. 1,b,c, a number of cracks
are already present on the initial irradiated surface.
According to [6], under uniaxial tension of a material
with hardened surface layer under conditions of ordinary
plastic deformation, a strong bending moment develops.
This is due to the incompatibility of deformation in the
hardened layer and at the base of the strained specimen.
The consequence of this is the emergence of
concentration of elastic stresses zones and, possibly, the
formation of cracks in the surface layer.
Therefore, apparently, during the deformation, the
opening of cracks in the surface layer partially proceeds
along the cracks already formed during crystallization,
and the formation and development of new cracks also
occurs.
Fig. 4. Different types of the surface of the working part
of the AK4-1 alloy specimen, previously irradiated by a
pulsed electron beam, and then deformed under
superplasticity to various degrees of deformation:
a – 15; b – 50; c – 260%
It should be noted that the formation and
development of cracks, also oriented approximately
perpendicular to the strain direction, is also observed
during superplastic deformation of unirradiated
specimens of this alloy.
However, the formation of these surface cracks
under the same temperature and strain rate conditions is
accompanied by the formation and development of
fibrous structures in them (Fig. 6).
The average diameter of such fibers is several
micrometers. The length of the fibers correlates with the
linear size of the surface cracks in the tension direction
and reaches 100 μm in the investigated alloy. The
formation of such fibers during high-temperature
superplastic deformation was observed in many
aluminum-based alloys [15–23].
Fig. 5. General view of the irradiated AK4-1 alloy
fracture surface superplastically deformed to fracture
under the optimal conditions
Fig. 6. Types of deformation relief and fibrous
formations in the working part of the alloy AK4-1
specimen superplastically deformed to fracture under
the optimal conditions to various deformation degrees
The causes of fiber formation and the mechanisms of
their development have also been studied in many
papers [17–23]. However, all the fiber formation
mechanisms discussed in the literature, cannot fully
explain their origin [17]. In papers [18–23] the
assumptions were put forward and developed that fibers
are formed and developed during the opening of cavities
and cracks as a result of the viscous flow of a liquid-
solid material located at the grain boundaries. Scheme of
kinetics of fiber formation and development during the
superplastic deformation is developed. It considers case
than specimens contain at intergranular boundaries areas
of viscous liquid phase [21].
Fig. 7 shows the thermogram, obtained as a result of
differential thermal analysis of alloy AK4-1 specimen,
which was heated from room temperature to a
temperature T = 860 °C with a heating rate of 5 °C/min.
Fig. 7. Curve of differential thermal analysis of the
alloy AK4-1 specimen
It can be seen that in the temperature range
(490…560 ºС), phase transformations take place in its
specimens, as a result of which heat is absorbed. I.e. it is
likely that the alloy is partially melted.
Mechanical tests of both irradiated and initial alloy
specimens were performed at the same temperatures.
Thus, during the superplastic deformation of both
irradiated and non-irradiated specimens, a liquid phase
could be present in their structure. However, fibrous
structures were found only in the surface layer of
unirradiated alloy specimens. Consequently, in the near-
surface layers of irradiated and unirradiated specimens
of alloy AK4-1, the deformation processes developed in
different ways. In the case of unirradiated specimens,
the separation of grains from each other in the process
of grain-boundary sliding led to the development of a
viscous flow of a liquid-solid material, which, as a result
of partial melting, formed at the grain boundaries. This
viscous flow, that is, the manifestation of the so-called
“microsuperplasticity” [18], led to the formation and
development of fibrous structures. In irradiated
specimens in the near-surface remelted layer, the
formation of filamentary structures does not occur, on
the surface they are actually absent. As is known [2–6],
the structure of a layer, remelted by an electron beam is,
as a rule, amorphous or nanocrystalline. On the one
hand, the creation of a nanocrystalline structural state
leads to an increase in strength, but to a decrease in
ductility [24]. However, nanocrystalline materials have
high rates of superplasticity. In addition, as shown in
[9], the surface layer, even from pure aluminum, which
does not initially have superplastic properties, can be
superplastic in the composition with magnesium alloy.
For this purpose, the interlayer must have very strong
connection. When the modified surface layer is firmly
bound to the base of alloy, the neck formation in the
surface layer is suppressed by uniform superplastic
deformation of the base part of the specimen [9]. In [9],
the connection between the specimen body and surface
layer was intermetallic from the Al3Mg2 phase.
However, the mechanical test temperature was much
lower than the melting point (Ti) of this phase.
Therefore, the surface layer was firmly connected to the
base of the specimen. In the case of the investigated
alloy AK4-1, the surface layer consists of the same
material, but it is in a different structural state. Between
these two layers there is a separating boundary [2].
However, the temperature of mechanical test has already
exceeded certain temperature (Ti) at which partial
melting of the alloy can occur. And, probably, the zones
of elastic stresses arising under the conditions of applied
stress relax by sliding of separate surface fragments
along the boundary of the layer connection.
Fig. 8 shows a diagram of the development of
deformation processes in the modified surface layer
under superplasticity conditions. Apparently, above a
certain temperature Ti, at which signs of local melting of
the material begin to appear, the surface modified layer
will no longer deform superplastically, but will simply
slide along the plane of interconnection of the layers,
separating into fragments.
Fig. 8. Schematic representation of the development of
deformation processes in the modified surface layer
under superplasticity conditions (1 is the base of the
alloy, 2 is the modified layer)
CONCLUSIONS
1. It is determined that the specimens of the alloy
AK4-1 exposed to irradiation have phenomenological
characteristics typical for superplasticity. The maximum
relative elongation of specimens deformed to failure
under the superplastic conditions is 230%. At the same
time, the presence of a surface layer with a more
equiaxed and fine-grained structure does not lead to a
significant improvement of the superplastic properties.
2. The state of the surface remelted layer after
deformation under the superplasticity conditions differs
from the general state of the deformed specimen. The
remelted layer has multiple fractures and delaminations.
The deformation processes occurring in the main part of
the specimen and in the layer remelted by a pulsed
electron beam are fundamentally different. While the
main part of the specimen, as is clear from the data of
mechanical tests, is superplastically deformed, the
surface of remelted layer is simply divided into
fragments, the boundaries of which are cracks formed
after crystallization of the remelted layer.
3. The state of the boundary between the surface
layer and the base of the specimen is of decisive
importance for the development of deformation
processes in the surface modified layer.
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Article received 14.02.2019
СВЕРХПЛАСТИЧЕСКАЯ ДЕФОРМАЦИЯ СПЛАВА АК4-1 С ПОВЕРХНОСТНЫМ
СЛОЕМ, ПЕРЕПЛАВЛЕННЫМ ИМПУЛЬСНЫМ ПУЧКОМ ЭЛЕКТРОНОВ
В.В. Брюховецкий, А.В. Пойда, В.П. Пойда, Д.Е. Милая
Образцы алюминиевого сплава АК4-1, предварительно облученные импульсным пучком электронов,
были продеформированы в условиях сверхпластичности. Изучены особенности структурных изменений в
ходе сверхпластической деформации предварительно облученных образцов. Показано, что деформационные
процессы, происходящие в основной части образца и в переплавленном импульсным пучком электронов
слое, имеют принципиальные различия.
НАДПЛАСТИЧНА ДЕФОРМАЦІЯ СПЛАВУ АК4-1 З ПОВЕРХНЕВИМ ШАРОМ,
ПЕРЕПЛАВЛЕНИМ ІМПУЛЬСНИМ ПУЧКОМ ЕЛЕКТРОНІВ
В.В. Брюховецький, А.В. Пойда, В.П. Пойда, Д.Є. Мила
Зразки алюмінієвого сплаву АК4-1, попередньо опромінені імпульсним пучком електронів, були
продеформовані в умовах надпластичності. Вивчено особливості структурних змін у ході надпластичної
деформації попередньо опромінених зразків. Показано, що деформаційні процеси, що відбуваються в
основній частині зразка і в переплавленому імпульсним пучком електронів шарі, мають принципові
відмінності.
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