共查询到20条相似文献,搜索用时 15 毫秒
1.
G. G. Zakharova E. G. Astafurova M. S. Tukeeva E. V. Naidenkin G. I. Raab S. V. Dobatkin 《Russian Physics Journal》2011,54(4):416-422
Using the method of equal-channel angular pressing (ECAP), submicrocrystalline structure is formed in lowcarbon Fe–Mn–V–Ti–C
steel with the average grain size 260 nm in the ferrite-perlite state and 310 nm in the martensitic state. It is established
that the ECAP treatment gives rise to improved mechanical properties (Hμ = 2.9 GPa, σ0 = 990 MPa in the ferrite-perlite and Hμ = 3.7 GPa, σ0 = 1125 MPa in martensitic states), decreased plasticity, and results in plastic flow localization under tensile loading.
The high strength properties formed by the ECAP are shown to sustain up to the annealing temperature 500°C. 相似文献
2.
The stress-strain curve of a polycrystalline duralumine (D1) is studied to find three basic deformation stages: linear hardening,
parabolic hardening (n = 1/2), and prefracture (n < 1/2). The results obtained show special features of macrolocalization
of the plastic flow of the alloy under review. The distribution patterns of localized plastic flow domains develop according
to deformation stages. The prefracture stage is characterized by self-correlated motion of the domains to the point of subsequent
fracture. It follows from an analysis of the plastic flow localization kinetics that both hardening and softening domains
coexist in the specimen in the prefracture stage. The domains move with a constant velocity inherent to each of them and linearly
dependent on the position of their nucleation point.
__________
Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 11, pp. 68–73, November, 2007. 相似文献
3.
L. B. Zuev S. A. Barannikova V. I. Danilov Yu. I. Chumlyakov I. V. Kireeva 《Technical Physics》1999,44(10):1179-1185
Experimental data on the evolution of macrodeformation fields of single-crystal samples of austenitic chromium-nickel steel
with a superequilibrium nitrogen content under tension are analyzed on the basis of a model of autowave plastic flow. The
conditions for the appearance and observation of different types of autowave deformation structures are established; such
structures include a solitary front, a traveling autowave, and a stationary dissipative structure and are determined by the
crystal-geometry of deformation and by the nitrogen concentration in the material. It is shown that a one-to-one correspondence
exists between the type of deformation autowave and the stage of the plastic flow curve of the material.
Zh. Tekh. Fiz. 69, 56–62 (October 1999) 相似文献
4.
S. P. Belyaev N. N. Resnina I. M. Uchaeva 《Bulletin of the Russian Academy of Sciences: Physics》2008,72(9):1288-1291
The effect of temperature and direction of preliminary torsion in the austenitic state on the degree of strain recovery upon heating of a TiNi alloy has been investigated. It is shown that an increase in the preliminary deformation temperature from 500 to 700 K leads to an increase in the degree of shape recovery upon heating of the material studied. In particular, a 20% strain at a temperature of 500 K decreases the recovery coefficient by 20%, whereas the same preliminary strain at 700 K deteriorates the shape recovery by only 4%. It is established that, applying preliminary torsion in the austenitic and martensitic states in opposite directions, one can obtain an increase in the shape memory strain with an increase in the preliminary plastic strain. Thus, at some plastic strains (λ pl > 10%), the strain recovered upon heating may even exceed the strain set in the martensitic state. 相似文献
5.
S. B. Kislitsin A. A. Klopotov A. I. Potekaev Yu. A. Timoshnikov 《Russian Physics Journal》2008,51(4):414-424
Based on structure investigations, a comprehensive effect of irradiation by gamma quanta on the structural steel hardened
to martensitic steel (multi-component alloy in a highly non-equilibrium structural-phase state due to martensitic transformations
occurring in it during hardening) is reported.
__________
Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 4, pp. 74–83, April, 2008. 相似文献
6.
H. Morawiec T. Goryczka J. Lelatko K. Prusik A. Drdzeń 《The European physical journal. Special topics》2008,158(1):93-98
Deformation of polycrystalline Ni-Mn-Ga alloys was
studied for both the L21 parent phase and 10 M martensitic state. The
effect of deformation by compression up to the fracture on mechanical
behavior and structure change was studied for the inhomogeneous as-cast
state and after annealing at 900○C for 50 hours. The structure, after
deformation of the parent phase, observed by TEM reveals the presence of 10 M
and 14 M martensite in the matrix, whereas the deformation of 10 M martensite
does not show the change of the structure type. The stress-strain curves
were analyzed and compared with the earlier published results. 相似文献
7.
The evolution of the perlite structure in the course of plastic deformation of U8 and St70 steels has been studied. With increasing
degree of cold working, the dislocation density increases near the interphase boundary in the ferrite interstices of perlite,
which forms a dislocational “fringe”, which in turn forms a pseudocellular structure. Under thermal deformation conditions,
a subgrain structure arises in the ferrite interstices of lamellar perlite. The most dangerous localized flow channels in
which plasticity is exhausted for the first time and cracks appear, are the deformation bands. The narrower the deformation
bands and the larger the value of the relative displacement of the subcolumn blocks adjacent to them, the more dangerous they
are with regard to failure. The features revealed in the development of deformation and failure provides a basis for controlling
steel treatment regimes in order to produce perlite with the optimum structural parameters.
Novosibirsk State Technical University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 7, pp. 3–10, July,
1996. 相似文献
8.
D.G. Park D.W. Kim C.S. Angani V.P. Timofeev Y.M. Cheong 《Journal of magnetism and magnetic materials》2008
The magnetic properties of stainless steel have been investigated using a radio frequency (RF) high-temperature superconductivity (HTS) SQUID (Superconducting QUantum Interference Device)-based susceptometer. The nuclear grade 304 stainless steel is nonmagnetic at a normal condition but it changes to a partially ferromagnetic state associated with martensitic transformation under a plastic deformation. The magnetic moment of the 304 stainless steels was increased with an increasing cold work rate, and decreased with an increasing annealing temperature. The change of mechanical properties such as yield strength and ultimate tensile strength (UTS) are also analyzed in terms of deformation-induced martensitic transformation. 相似文献
9.
L. M. Utevskii L. V. Skibina M. N. Pankova M. M. Chernik 《Bulletin of the Russian Academy of Sciences: Physics》2010,74(11):1497-1500
The features of martensitic transformations upon the low-temperature (1.8–300 K) deformation of metastable Fe-18Cr-10Ni and
Fe-18Cr-15Ni alloy single crystals with low stacking-fault energies were studied. It was shown that the γ → ɛ and γ → α martensitic
transformations play the main role in increasing strength and plasticity when the deformation temperature is reduced to 4.2
K. 相似文献
10.
E. F. Dudarev V. N. Tokarev A. I. Lotkov G. P. Bakach V. N. Grishkov 《Russian Physics Journal》1998,41(1):21-29
The levels of inelastic martensitic strain of polycrystals during a thermoelastic martensitic transformation under a load
are discussed. The example ofTi(Ni-Cu-Fe) alloys with the B2 structure was used to study the role of microlevel and mesolevels in inelastic martensitic deformation
during cooling of polycrystals under a load and loads in different initial structural states.
V. D. Kuznetsov Siberian Physicotechnical Institute at Tomsk State University. Institute of Physics of Strength of Materials
and Materials Science, Siberian Branch of the Academy of Sciences of the USSR, Tomsk. Translated from Izvestiya Vysshikh Uchebnykh
Zavedenii, Fizika, No. 1, p. 35–46, January, 1998. 相似文献
11.
P. A. Khaimovich 《Russian Physics Journal》2007,50(11):1079-1083
Roles of temperature and hydrostatic stress forces in severe plastic deformation of metal objects are considered. Methods
and devices are described that allow the structural states of metal with high mechanical characteristics to be obtained upon
plastic deformation at low temperatures under conditions of hydrostatic stress.
__________
Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 11, pp. 13–16, November, 2007. 相似文献
12.
G. Abrosimova A. Aronin O. Barkalov D. Matveev O. Rybchenko V. Maslov V. Tkach 《Physics of the Solid State》2011,53(2):229-233
The effect of multiple rolling at room temperature on the structure and crystallization of the Al85Ni6.1Co2Gd6Si0.9 amorphous alloy has been studied using transmission electron microscopy, differential scanning calorimetry, and X-ray diffraction.
The total plastic strain is 33%. It has been shown that the deformation results in the formation of aluminum nanocrystals
with the average size that does not exceed 10–15 nm. The nanocrystals are formed in regions of localization of plastic deformation.
The deformation decreases the thermal effect of nanocrystallization (∼15%) as compared to the heat release at the first stage
of crystallization of the unstrained sample. The morphology, structure, and distribution of precipitates have been investigated.
Possible mechanisms of the formation of nanocrystals during the deformation have been discussed. 相似文献
13.
Variation of the velocity of ultrasound propagation in polycrystalline aluminum under plastic deformation is studied. The dependences of the velocity of ultrasound on the strain and the actual stress are found to consist of three distinct stages. The study of the complex shapes of these dependences allows one to reveal additional stages in the parabolic stress-strain curve of the plastic flow, these features being impossible to observe by conventional methods. The behavior of the ultrasonic velocity observed in the experiment is explained by the changes in the defect structure of the material under deformation. 相似文献
14.
On the basis of a calculation of the structural relaxation rate and an experimental acoustical-emission determination of the
temperature of the transition from localized to uniform flow it is argued that the type of plastic deformation of metallic
glasses is uniquely determined by the kinetic structure of the relaxation. In the case of a kinetically hindered structural
relaxation, which is characteristic for tests of initial samples at temperatures T<380–420 K, a localized dislocational deformation is realized. At higher temperatures, “memory” of the thermal prehistory
of the samples is lost (aging at room temperature), the structural relaxation rate grows abruptly and plastic flow becomes
uniform viscoplastic flow.
Fiz. Tverd. Tela (St. Petersburg) 41, 2167–2173 (December 1999) 相似文献
15.
Kozlov É. V. Popova N. A. Ignatenko L. N. Teplyakova L. A. Klopotov A. A. Koneva N. A. 《Russian Physics Journal》2002,45(3):285-302
The phase and structure transformation of tempered martensitic steel in the course of plastic deformation is considered in the present paper. A close correlation between the evolution of the substructure type and the behavior of carbon is established. The carbon concentrations in solid solution and on crystalline defects of the material as a whole and in different dislocation substructures are investigated versus the degree of plastic strain. 相似文献
16.
A. N. Tyumentsev I. A. Dietenberg E. A. Korznikova A. V. Korznikov K. I. Denisov V. M. Chernov 《Russian Physics Journal》2011,53(12):1295-1304
Using electron microscopy, an investigation is performed of microstructure features of re-orientation microbands formed in
nickel and V–4Ti–4Cr alloys under severe plastic deformation in the Bridgman anvils. It is shown that their formation could
be described within the framework of a quasi-elastic mechanism of motion of partial-disclination dipoles, which is controlled
by the flows of non-equilibrium point defects in the fields of local gradients of normal stress-tensor components. Operation
of this mechanism offers an additional advantage of nanostructuring the defect substructure during plastic deformation of
metallic materials, followed by formation of the structure states wherein the nanocrystallites measure a few nanometers. 相似文献
17.
利用有限元模拟方法研究了内凹负泊松比蜂窝结构的面内双轴冲击响应。用节点扰动方法建立了具有不同规则度的内凹负泊松比蜂窝结构,并将其在不同冲击速度下的变形模态、应力-应变曲线和能量耗散能力与规则蜂窝进行了对比分析。结果表明,冲击速度是内凹蜂窝结构变形模态最主要的影响因素。此外,在双轴冲击下,由于不规则度的引入,延长了应力-应变曲线的平台阶段,抑制了结构的各向异性程度,从而使结构的变形特征从局部密实转向整体密实。在能量吸收能力方面,结构的不规则性导致了密实化阶段的滞后,因此在相同的压缩程度下,其塑性耗散能低于规则模型。 相似文献
18.
A. V. Panin M. S. Kazachenok Yu. I. Pochivalov Yu. F. Ivanov A. A. Panina 《Russian Physics Journal》2009,52(1):85-93
Methods of diffraction electron microscopy have been used to examine the types of dislocation substructures formed in the
surface layer of armco-iron specimens subjected to ultrasonic treatment. It is shown that banded or equiaxed ultrafine-grained
structure can be generated in the material depending on its initial structural state. The special features of the plastic
deformation and fracture of the ultrafine-grained surface layers of the specimens under uniaxial tension are described. The
extent to which the mechanical properties of the examined material are improved by ultrasonic treatment has been found to
depend on its initial state.
Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 1, pp. 74–82, January, 2009. 相似文献
19.
The evolution of the atomic structure of face-centered cubic (fcc) and body-centered cubic (bcc) crystals under the conditions
of pulsed external loads and large plastic strains is investigated on the basis of computer experiments. The crystals are
strained in steps to 32%. After each deformation step (2%), the system is relaxed by molecular dynamics to a new equilibrium
state at 300 K. The results of the computer experiments show that plastic deformation can take place under instantaneous external
loads either as a result of the motion of partial dislocations, twinning, or the turning and displacement of atomic planes,
depending on the stage of the process. The laws governing the variation of the potential energy of the system and the rotation
angle of the atomic planes as functions of the degree of plastic strain of the crystal are found.
Zh. Tekh. Fiz. 67, 100–102 (December 1997) 相似文献
20.
A study is made of the mechanism of plastic deformation at the mesoscale level in flat specimens of aluminum polycrystals.
The mechanism is examined with the use of high-resolution optical-television system TOMSC-1. It is shown that a multilevel
mesoscale structure is formed in the specimen as it is deformed. The formation of this structure leads to the appearance of
two types of stationary waves 120 μm and 4.8 mm long. The results are interpreted within the framework of a hierarchy of mesoscale
levels of deformation and are linked with the decisive role of surface oxide films in the formation of the mesoband structure
and stationary waves associated plastic flow.
Institute of the Physics of Strength and Materials Science, Siberian Branch of the Russian Academy of Sciences. Translated
from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 1, pp. 31–39, January, 1997. 相似文献