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1

Jenei, Péter, Guy Dirras, Jenő Gubicza, and Hervé Couque. "Deformation Mechanisms in Ultrafine-Grained Zn at Different Strain Rates and Temperatures." Key Engineering Materials 592-593 (November 2013): 313–16. http://dx.doi.org/10.4028/www.scientific.net/kem.592-593.313.

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The deformation mechanisms in ultrafine-grained hexagonal close packed Zn were investigated at different strain rates and temperatures. The influence of grain size on the deformation mechanisms was revealed by comparing the results obtained on ultrafine-grained and coarse-grained Zn. It was found that for coarse-grained Zn at room temperature and strain rates lower than 10-2s-1twinning contributed to plasticity besides dislocation activity. For strain rates higher than 103s-1the plasticity in coarse-grained Zn was controlled by dislocation drag. In ultrafine-grained Zn the relatively large dis
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2

Nazé, Loic, and Jean Loup Strudel. "Strain Rate Effects and Hardening Mechanisms in Ni Base Superalloys." Materials Science Forum 638-642 (January 2010): 53–60. http://dx.doi.org/10.4028/www.scientific.net/msf.638-642.53.

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The mechanical properties of nickel superalloys are related to the spatial distribution of hardening phases, their size and composition, and on the configurations of dislocations introduced by plastic and viscoplastic straining. Heterogeneous plastic flow in relation with dynamic strain aging is examined and synthesized. Dislocations are usually faced with the alternative of shearing or bypassing the ’ phase occupying up to 60 vol.%. Depending on ’ size, several Orowan bypassing mechanisms are observed, alternatively shearing by dislocation pairs or complex configurations involving S-ISF and
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3

Mughrabi, Haël. "On the dislocation mechanisms of dynamic strain ageing in fatigued plain carbon steels." International Journal of Materials Research 94, no. 5 (2003): 471–77. http://dx.doi.org/10.1515/ijmr-2003-0085.

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Abstract The fatigue life of plain ferritic carbon steels fatigued in stress-controlled (plastic-strain-controlled) tests exhibits a maximum (minimum) at a temperature of approx. 300 °C as a result of dynamic strain ageing (DSA). In the regime of DSA, an enhanced cyclic hardening related to an increased dislocation density is observed, and the dislocation arrangement changes from a dislocation cell structure (at intermediate stress amplitudes) at room temperature to a dense edge di-/multipolar bundle/wall/vein structure in the temperature range of DSA and back to a dislocation cell/ subgrain s
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4

He, Yang-Yu, Zhao-Hui Zhang, Yi-Fan Liu, et al. "Ultra-High Strength and Specific Strength in Ti61Al16Cr10Nb8V5 Multi-Principal Element Alloy: Quasi-Static and Dynamic Deformation and Fracture Mechanisms." Materials 18, no. 14 (2025): 3245. https://doi.org/10.3390/ma18143245.

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This study investigates the deformation and fracture mechanisms of a Ti61Al16Cr10Nb8V5 multi-principal element alloy (Ti61V5 alloy) under quasi-static and dynamic compression. The alloy comprises an equiaxed BCC matrix (~35 μm) with uniformly dispersed nano-sized B2 precipitates and a ~3.5% HCP phase along grain boundaries, exhibiting a density of 4.82 g/cm3, an ultimate tensile strength of 1260 MPa, 12.8% elongation, and a specific strength of 262 MPa·cm3/g. The Ti61V5 alloy exhibits a pronounced strain-rate-strengthening effect, with a strain rate sensitivity coefficient (m) of ~0.0088 at 0.
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5

Shimokawa, Tomotsugu, Toshiyasu Kinari, and Sukenori Shintaku. "Atomic Simulations on the Grain Subdivision of a Crystalline Metal." Materials Science Forum 561-565 (October 2007): 1983–86. http://dx.doi.org/10.4028/www.scientific.net/msf.561-565.1983.

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The relationship between grain subdivision mechanisms of a crystalline metal and the strain gradient under severe plastic deformation is studied by using molecular dynamics simulations in quasi two dimensions. Two problems are simulated for single crystal models: (a) uniaxial tensile and compressive deformation and (b) localized shear deformation. In the case of uniaxial deformation, a large number of dislocation pairs with opposite Burgers vectors are generated under deformation, but most dislocations are vanished due to pair annihilation under relaxation. Therefore, no dislocation boundary c
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6

Belyakov, Andrey, Marina Odnobokova, Iaroslava Shakhova, and Rustam Kaibyshev. "Regularities of Microstructure Evolution and Strengthening Mechanisms of Austenitic Stainless Steels Subjected to Large Strain Cold Working." Materials Science Forum 879 (November 2016): 224–29. http://dx.doi.org/10.4028/www.scientific.net/msf.879.224.

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The deformation microstructures and their effects on mechanical properties of austenitic stainless steels processed by cold rolling at ambient temperature to various total strains were studied. The cold working was accompanied by the development of strain-induced martensitic transformation because of meta-stable austenite at room temperature. The strain-induced martensitic transformation and deformation twinning promoted the grain refinement during cold rolling, leading to nanocrystalline structures consisting of a mixture of austenite and martensite grains with their transverse grain sizes of
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7

Solov’eva, Yu V., A. N. Solov’ev, M. V. Gettinger, O. D. Pantyukhova, and V. A. Starenchenko. "Contributions of various mechanisms to the flow stress in Cu – 12 at. % Al single crystals." Deformation and fracture of materials, no. 1 (2022): 19–26. http://dx.doi.org/10.31044/1814-4632-2022-1-19-26.

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The evolution of the structure in the process of plastic deformation by compression of Cu – 12 at.% Al single crystals is investigated. Data on the stress-strain curve, deformation stages and the relationship of stages with the types of forming substructures are presented. Quantitative measurements of various parameters characterizing the substructures were carried out. The results are presented in the form of a diagram of the dependence of the fraction of substructures on the density of dislocations. Dependences of the distances between non-reactive intersections of dislocations, inter-disloc
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8

Chang, Shou-Yi, Yi-Chung Huang, Shao-Yi Lin, Chia-Ling Lu, Chih Chen, and Ming Dao. "In Situ Study of Twin Boundary Stability in Nanotwinned Copper Pillars under Different Strain Rates." Nanomaterials 13, no. 1 (2023): 190. http://dx.doi.org/10.3390/nano13010190.

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The nanoscopic deformation of ⟨111⟩ nanotwinned copper nanopillars under strain rates between 10−5/s and 5 × 10−4/s was studied by using in situ transmission electron microscopy. The correlation among dislocation activity, twin boundary instability due to incoherent twin boundary migration and corresponding mechanical responses was investigated. Dislocations piled up in the nanotwinned copper, giving rise to significant hardening at relatively high strain rates of 3–5 × 10−4/s. Lower strain rates resulted in detwinning and reduced hardening, while corresponding deformation mechanisms are propo
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9

Lee, W.-S., C.-F. Lin, and B.-T. Chen. "Tensile properties and microstructural aspects of 304L stainless steel weldments as a function of strain rate and temperature." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 219, no. 5 (2005): 439–51. http://dx.doi.org/10.1243/095440605x17045.

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This paper presents an investigation into the effects of loading rate and temperature on the tensile properties and microstructural evolution of 304L stainless steel weldments. The stress-strain behaviour during tension was determined by loading specimens in a material testing system at strain rates ranging from 10−3 to 10−1 s−1 and temperatures between −100 and 500°. Extensive quantitative microstructural examinations were performed to identify the correlation between the tensile response and the substructure of dislocations and α’ martensite. It was found that the tensile flow stress increas
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10

Kvam, E. P., D. M. Maher, and C. J. Humphreys. "Variation of dislocation morphology with strain in GexSi1−x epilayers on (100)Si." Journal of Materials Research 5, no. 9 (1990): 1900–1907. http://dx.doi.org/10.1557/jmr.1990.1900.

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A change in microstructure, including dislocation Burgers vector, length, and behavior, has been observed to occur when the epilayer mismatch is varied in GexSi1−x layers grown on (100) Si. At low mismatches (<1.5%), there is an orthogonal array of very long 60° misfit dislocations. At higher mismatches (>2.3%) there is an orthogonal array of short edge dislocations. At intermediate mismatches (1.5 to 2.3%) there is a mixture of 60° and edge dislocations. The nature of the microstructure has a pronounced effect on the density of threading dislocations in the epilayer, which increase by a
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11

Popova, Natalyi, Mikhail Slobodyan, Anatoliy Klopotov, Elena Nikonenko, Alexander Potekaev, and Vladislav Borodin. "Relationship of Internal Stress Fields with Self-Organization Processes in Hadfield Steel under Tensile Load." Metals 13, no. 5 (2023): 952. http://dx.doi.org/10.3390/met13050952.

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The effect of tensile strains on the microstructure of Hadfield steel was studied by transmission electron microscopy (TEM). Stages of the obtained stress–strain curves were observed, and correlated well with the evolution of the dislocation substructure. Based on an analysis of TEM images, quantitative parameters were determined, such as the material volume fractions, in which slip and twinning occurred, as well as twinning, which developed in one, two and three systems. Some transformation mechanisms were reported that caused great hardening of Hadfield steel. In particular, a complex defect
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12

Astafurova, Elena, Anastasiya Fortuna, Evgenii Melnikov, and Sergey Astafurov. "The Effect of Strain Rate on Hydrogen-Assisted Deformation Behavior and Microstructure in AISI 316L Austenitic Stainless Steel." Materials 16, no. 8 (2023): 2983. http://dx.doi.org/10.3390/ma16082983.

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The influence of strain rate in the interval of (10−5–10−3) 1/s on room temperature tensile behavior, dislocation arrangement, deformation mechanisms, and fracture of austenitic stainless steel AISI 316L electrochemically charged with hydrogen was investigated. Independently on strain rate, hydrogen charging provides the increase in the yield strength of the specimens due to a solid solution hardening of austenite, but it slightly influences deformation behavior and strain hardening of the steel. Simultaneously, hydrogen charging assists surface embrittlement of the specimens during straining
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13

Ni, Hai, and Zhirui Wang. "Dislocation mechanisms of mean stress effect on cyclic plasticity." Materials Testing 46, no. 7-8 (2004): 363–73. http://dx.doi.org/10.1515/mt-2004-0363.

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Abstract The dislocation mechanisms behind sagging behavior of autosuspension spring steels are far from being understood due to their complicated microstructures. In this study, systematic cyclic loading tests were carried out on two model materials - industrial pure iron and spheroidized 1045 steel – to understand the mechanisms behind sagging. It is found that it is the different dislocation microstructures that control the cyclic creep behavior of different materials. With iron samples with low mean stress values, higher mean stresses do not trigger cell structure formation mainly due to t
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14

Gan, Kefu, and Zhiming Li. "Unveiling the role of glassy nanodomains in strength and plasticity of crystal–glass nanocomposites via atomistic simulation." Journal of Applied Physics 131, no. 8 (2022): 085109. http://dx.doi.org/10.1063/5.0080746.

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Crystalline metals and alloys are usually ductile owing to lattice dislocations and various slip systems, while bulk metallic glasses show ultrahigh yield strength with very limited plasticity. Combining the crystalline and glassy phases in one alloy has recently been shown to be promising for achieving both ultrahigh strength and good deformability. Yet, it is challenging to capture the dynamic dislocation behavior through the deformation process and elucidate the role of glassy domains on the excellent mechanical performance of the nanocomposites. Here, we unveil and visualize the atomic-sca
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15

Xie, Bin, Xinyu Wang, Yongsheng Fan, and Ruizhi Li. "Atomistic Investigation on the Strengthening Mechanism of Single Crystal Ni-Based Superalloy under Complex Stress States." Metals 12, no. 5 (2022): 889. http://dx.doi.org/10.3390/met12050889.

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Single crystal Ni-based superalloy, with excellent mechanical properties in high temperature, always works under complex stress states, including multiaxial tension and compression, which results in various strengthening mechanisms. In this paper, the atomistic simulation is applied to investigate the microstructure evolution under complex mechanical loading conditions, including uniaxial, equibiaxial, and non-equibiaxial tensile–compressive loadings. By comparison of the strain–stress curves and analysis of dislocation motion, it is believed that the tension promotes the bowing out of disloca
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16

Luo, J. F., S. C. Mao, X. D. Han, G. Chen, Z. Zhang, and M. H. Wu. "High-Cycle Fatigue Mechanisms of a NiTi Shape Memory Alloy under Different Mean Strains." Materials Science Forum 610-613 (January 2009): 1120–27. http://dx.doi.org/10.4028/www.scientific.net/msf.610-613.1120.

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The high-cycle fatigue mechanisms of a NiTi shape memory alloy (SMA) under three different mean strains were investigated. Cold-rolled NiTi SMA specimens were heat treated at 600°C for 30min was selected to perform the fatigue test. Three samples were conducted cyclic deformation up to 2×105 cycles with three mean strains that subjected at full austenite, total stress-induced martensite (SIM) and austenite-martensite coexist status with the same strain amplitude of 0.25%. The cyclic stress-strain (CSS) curves show different cyclic softening and hardening at different mean strains. The S-S curv
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17

Shi, Guo-Jie, Jin-Guo Wang, Zhao-Yang Hou, Zhen Wang, and Rang-Su Liu. "Simulation study of the effect of strain rate on the mechanical properties and tensile deformation of gold nanowire." Modern Physics Letters B 31, no. 27 (2017): 1750247. http://dx.doi.org/10.1142/s0217984917502475.

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The mechanical properties and deformation mechanisms of Au nanowire during the tensile processes at different strain rates are revealed by the molecular dynamics method. It is found that the Au nanowire displays three distinct types of mechanical behaviors when tensioning at low, medium and high strain rates, respectively. At the low strain rate, the stress–strain curve displays a periodic zigzag increase–decrease feature, and the plastic deformation is resulted from the slide of dislocation. The dislocations nucleate, propagate, and finally annihilate in every decreasing stages of stress, and
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18

Fu, Xueqiong. "Nanostructure, Plastic Deformation, and Influence of Strain Rate Concerning Ni/Al2O3 Interface System Using a Molecular Dynamic Study (LAMMPS)." Nanomaterials 13, no. 4 (2023): 641. http://dx.doi.org/10.3390/nano13040641.

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The plastic deformation mechanisms of Ni/Al2O3 interface systems under tensile loading at high strain rates were investigated by the classical molecular dynamics (MD) method. A Rahman–Stillinger–Lemberg potential was used for modeling the interaction between Ni and Al atoms and between Ni and O atoms at the interface. To explore the dislocation nucleation and propagation mechanisms during interface tensile failure, two kinds of interface structures corresponding to the terminating Ni layer as buckling layer (Type I) and transition layer (Type II) were established. The fracture behaviors show a
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19

Beyerlein, Irene J. "Plastic Behavior of Metals in Reverse Straining after Large Pre-Strains." Materials Science Forum 579 (April 2008): 41–60. http://dx.doi.org/10.4028/www.scientific.net/msf.579.41.

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The present work examines the reversal response of a face-centered cubic (fcc) polycrystalline metal after large pre-strains. While reversal responses among different fcc metals are similar after small pre-strains, they can vary widely after large pre-strains depending on material and microstructure. In this article, these characteristics are considered to be governed by three distinct mechanisms: (1) reverse glide of dislocations previously held by backstresses, (2) reverse glide of dislocations previously held by barriers, and (3) ‘reverse hardening’ by reverse glide over stable dislocation
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20

Fu, Xueqiong. "Plastic deformation of Ag/MgO interface system during tensile fracture: a molecular dynamics study." Applied and Computational Engineering 7, no. 1 (2023): 351–57. http://dx.doi.org/10.54254/2755-2721/7/20230557.

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Fracture experiments on layered metal-ceramic composites show that the plastic dissipation in the metal near the crack tip accounts for most of the macroscopic fracture toughness. In this work we studied the microscopic plastic deformation mechanisms of Ag/MgO interface systems using molecular dynamics (MD) method. As tensile strain increases, lattice dislocations nucleate at interface misfit dislocations and propagate in metal layer. The formation of immobile Hirth dislocations in Ag causes hardening. As the metal layer increases, the yield strength decreases and the hardening range is shorte
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21

Murr, L. E. "Microstructure-property hypermaps for shock-loaded materials." Proceedings, annual meeting, Electron Microscopy Society of America 44 (August 1986): 416–19. http://dx.doi.org/10.1017/s0424820100143675.

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Residual deformation-induced metallurgical effects or structure (microstructure)-property relationships are now generally well documented to be the result of stress or strain-induced microstructures, or microstructural changes in polycrystalline metals and alloys. In many cases, strain hardening, work hardening, or other controlling deformation mechanisms can be described by the generation, movement, and interactions of dislocations and other crystal defects which produce drag, or a range of impedances, including obstacles to dislocation motion.
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22

Gao Feng, Li Huan-Qing, Song Zhuo, and Zhao Yu-Hong. "The Evolution of Grain Boundary Dislocations in Graphene Induced by Strain: Three-Mode Phase-Field Crystal Method." Acta Physica Sinica 73, no. 24 (2024): 0. http://dx.doi.org/10.7498/aps.73.20241368.

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The evolution and role mechanisms of grain boundary structures during the deformation process of graphene are of great significance for understanding the deformation behavior of graphene and optimizing its mechanical properties. This article takes single-layer graphene as the research object and establishes a double crystal graphene model using the three-mode phase-field crystal method, deeply exploring the evolution mechanisms of dislocations at small-angle symmetrical tilt grain boundaries in graphene under strain. In view of the relaxation and deformation process, the relationship between t
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23

Mitra, R., A. Chiou, and J. R. Weertman. "In Situ Study of Deformation Mechanisms in Sputtered Free-Standing Nanocrystalline Nickel Films." Journal of Materials Research 19, no. 4 (2004): 1029–37. http://dx.doi.org/10.1557/jmr.2004.0134.

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Nickel films of 1.5–10-μm thickness, produced by dc magnetron sputtering and with disperse grain size distributions peaking in the 30–60-nm range, were subject to in situ tensile straining in a transmission electron microscope. The deformation was stopped frequently, while keeping the load applied, for transmission electron microscopy observation of the internal structure. Contrast changes occurred in many of the grains between strain increments. Ample evidence was seen of dislocation activity, which appears to be the major mechanism for deformation of the samples. Dislocations were seen in gr
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24

Li, R. N., H. Y. Song, M. X. Xiao, and M. R. An. "Atomic-scale insight into interaction mechanism between screw dislocation and HCP phase in high-entropy alloy." Journal of Applied Physics 133, no. 3 (2023): 034302. http://dx.doi.org/10.1063/5.0130784.

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The face-centered cubic (FCC)/hexagonal close-packed (HCP) dual-phase structure is a new design strategy proposed in recent years to achieve high strength and excellent plasticity of high-entropy alloys (HEAs). Here, the effect of HCP phase thickness, strain rate, and temperature on the interaction mechanism between screw dislocation and the HCP phase in the FCC structured CoCrFeMnNi HEAs is investigated by molecular dynamics simulation. The results show that there are two types of interaction modes between dislocations and the HCP phase: one is the dislocation passing through the HCP phase, t
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25

Long, Anping, Xiaoshan Liu, Lei Xiao, et al. "Anisotropy in the Creep–Fatigue Behaviors of a Directionally Solidified Ni-Based Superalloy: Damage Mechanisms and Life Assessment." Crystals 15, no. 5 (2025): 429. https://doi.org/10.3390/cryst15050429.

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Aero-engine turbine vanes made from directionally solidified nickel-based superalloys often fail with crack formation from the external wall of cooling channels. Therefore, this study simulates the compressive load on the external wall of the vane and conducts a sequence of creep–fatigue evaluations at 980 °C to investigate the creep–fatigue damage mechanisms of a directionally solidified superalloy and to assess its life. It is found that at low strain ranges, creep damage is dominant, with creep cavities forming inside the specimen and fatigue sources mostly distributed in the specimen inter
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26

Paulauskas, Tadas, Christopher Buurma, Eric Colegrove, et al. "Atomic scale study of polar Lomer–Cottrell and Hirth lock dislocation cores in CdTe." Acta Crystallographica Section A Foundations and Advances 70, no. 6 (2014): 524–31. http://dx.doi.org/10.1107/s2053273314019639.

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Dislocation cores have long dominated the electronic and optical behaviors of semiconductor devices and detailed atomic characterization is required to further explore their effects. Miniaturization of semiconductor devices to nanometre scale also puts emphasis on a material's mechanical properties to withstand failure due to processing or operational stresses. Sessile junctions of dislocations provide barriers to propagation of mobile dislocations and may lead to work-hardening. The sessile Lomer–Cottrell and Hirth lock dislocations, two stable lowest elastic energy stair-rods, are studied in
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27

Svirina, J. V., and V. N. Perevezentsev. "ON THE INFLUENCE OF NON-EQUILIBRIUM VACANCIES ON THE CHARACTERISTICS OF STRAIN INDUCED BROKEN DISLOCATION BOUNDARIES." Problems of Strength and Plasticity 86, no. 1 (2024): 5–14. http://dx.doi.org/10.32326/1814-9146-2024-86-1-5-14.

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The influence of material supersaturation with deformation vacancies on the characteristics of broken dislocation boundaries that appear near wedge disclinations as a result of accommodative plastic deformation is considered. An analysis is made for the elastic and osmotic forces acting on the dislocations of the broken boundary. Using discrete dislocation dynamics method, computer simulation of the nonconservative motion (climb) of dislocations in the boundary plane has been carried out. The broken boundary formed as a result of the splitting of the original disclination into two partial with
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28

Nixon, R. D., J. B. Posthill, R. F. Davis, H. R. Baumgartner, and B. R. Rossing. "Correlation of steady-state creep and changing microstructure in polycrystalline SiC sintered with powder derived via gaseous reactants in an are plasma." Journal of Materials Research 3, no. 5 (1988): 1021–30. http://dx.doi.org/10.1557/jmr.1988.1021.

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The mechanisms of steady-slate creep in compression in a sintered SiC produced via sintering of β-SiC powders derived from gaseous reactants in a plasma are have been determined from (1) kinetic data within the ranges of temperature and constant stress of 1770–2020 K and 17–208 MPa, respectively, and (2) the results of transmission electron microscopy (TEM) and other microbeam characterization techniques. The stress exponent was 2.06 ± 0.04; the values of activation energy were 913 ± 13 and 630 ± 14 kJ/mol above and below, respectively, a knee of ∼∼ 1920 K. Gliding dislocations and B4C precipi
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29

Huang, Wen Lai, Lin Zhang, Kaiguo Chen, and Guo Lu. "Mesoscale Mechanisms in Viscoplastic Deformation of Metals and Their Applications to Constitutive Models." Materials 14, no. 16 (2021): 4667. http://dx.doi.org/10.3390/ma14164667.

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Deformation of metals has attracted great interest for a long time. However, the constitutive models for viscoplastic deformation at high strain rates are still under intensive development, and more physical mechanisms are expected to be involved. In this work, we employ the newly-proposed methodology of mesoscience to identify the mechanisms governing the mesoscale complexity of collective dislocations, and then apply them to improving constitutive models. Through analyzing the competing effects of various processes on the mesoscale behavior, we have recognized two competing mechanisms govern
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30

Groiss, Heiko. "Dislocation Analysis in SiGe Heterostructures by Large-Angle Convergent Beam Electron Diffraction." Crystals 10, no. 1 (2019): 5. http://dx.doi.org/10.3390/cryst10010005.

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Dislocations play a crucial role in self-organization and strain relaxation mechanisms in SiGe heterostructures. In most cases, they should be avoided, and different strategies exist to exploit their nucleation properties in order to manipulate their position. In either case, detailed knowledge about their exact Burgers vectors and possible dislocation reactions are necessary to optimize the fabrication processes and the properties of SiGe materials. In this review a brief overview of the dislocation mechanisms in the SiGe system is given. The method of choice for dislocation characterization
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31

Pettinari-Sturmel, Florence, Joël Douin, Didier Locq, Pierre Caron та Armand Coujou. "Decorrelated Dislocation Movement in the γ-Matrix Channels of a Ni-Based Superalloy: Experiment and Dislocation Dynamics Simulation". Advanced Materials Research 278 (липень 2011): 13–18. http://dx.doi.org/10.4028/www.scientific.net/amr.278.13.

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The mechanical behavior of the polycrystalline NR3 Ni-based superalloy has been investigated at the microscopic scale. The elementary deformation mechanisms have been analyzed using transmission electron microscope observations as well as in situ straining experiments. Under low stress and relatively low strain rate conditions, a large variety of shearing micromechanisms has been observed depending on the local microstructure and the local effective stress. The influence of the smallest precipitates on the creep behavior has been enlightened: they induce narrow channels which act as obstacle f
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32

Jiang, Yunqing, Tongfei Zou, Meng Liu, et al. "Temperature and Strain Rate Dependence on the Tensile Mechanical Properties, Constitutive Equations, and Fracture Mechanisms of MarBN Steel." Materials 16, no. 8 (2023): 3232. http://dx.doi.org/10.3390/ma16083232.

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The effect of strain rate and temperature on the thermomechanical behavior and microstructure of MarBN steel is studied with the strain rates of 5 × 10−3 and 5 × 10−5 s−1 from room temperature (RT) to 630 °C. At high strain rates of 5 × 10−3 s−1, the Holloman and Ludwigson equations can better predict tensile plastic properties. In contrast, under low strain rates of 5 × 10−5 s−1, coupling of the Voce and Ludwigson equations appears to predict the flow relationship at RT, 430, and 630 °C. However, the deformation microstructures have the same evolution behavior under strain rates and temperatu
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33

Vecchio, Kenneth S. "Thermally induced dislocation generation in Al/Al2O3 metal-matrix composites." Proceedings, annual meeting, Electron Microscopy Society of America 49 (August 1991): 588–89. http://dx.doi.org/10.1017/s0424820100087252.

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It has been well documented that when a large difference in the coefficients of thermal expansion (CTE) exist between the matrix and reinforcement in metal-matrix composites (MMCs) internal stresses can develop which are sufficiently high to generate dislocations at the reinforcement/matrix interface. Numerous observations have been made of this phenomenon via TEM which have shown a variety of different dislocation substructures and dislocation punching mechanisms. An important consequence of this phenomenon is that the metal matrix becomes strain hardened as the dislocation density increases,
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34

Zhang, Zihao, Chengpeng Yang, Yizhong Guo, et al. "Direct Observation of the Deformation Mechanism of Twin-Structured Ni NWs under Bending Strain." Metals 12, no. 10 (2022): 1623. http://dx.doi.org/10.3390/met12101623.

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In situ atomic-scale bending tests of twin-structured Ni nanowires were realised using a homemade deformation device. The results showed that the plastic deformation mechanism in twin-structured Ni nanowires depended on the deformation stage. At the early stages of bending deformation, the plasticity of twin-structured Ni nanowires was controlled by dislocations interacting with the twin boundaries or parallel to them. With increasing bending strain, both dislocation and face-centred cubic–body-centred tetragonal phase transition occurred. At very high bending strain, grain boundaries resultin
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35

Chai, Guo Cai. "Low Cycle Fatigue Behavior and Mechanism of Newly Developed Advanced Heat Resistant Austenitic Stainless Steels at High Temperature." Advanced Materials Research 891-892 (March 2014): 377–82. http://dx.doi.org/10.4028/www.scientific.net/amr.891-892.377.

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Austenitic stainless steel grade UNS S31035 (Sandvik Sanicro® 25) has been developed for the next generation of 700°C A-USC power plant. This paper will mainly focus on the study of low cycle fatigue behavior and damage mechanisms of the material at room temperature, 600C to 700C by using electron back scatter diffraction and electron channeling contrast image techniques. At room temperature, the material shows a hardening and softening behavior as usual. At high temperature, however, it shows only a cyclic hardening behavior. Dynamic strain ageing can be one of the mechanisms. The damage and
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36

Hwang, R. Q. "Characterization of Dislocation Reactivity and Dynamics in Thin Metal Films Using Scanning Tunneling Microscopy." Microscopy and Microanalysis 6, S2 (2000): 702–3. http://dx.doi.org/10.1017/s143192760003600x.

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The accommodation of strain in metal films can lead to complex phenomena, both structurally and chemically. It can generically lead to the formation of dislocations. These dislocations play an important role in defining the evolution and response of the film to further growth and external forces. The structures of the dislocations are directly analogous to bulk dislocations, but their properties are very different due to the presence of the surface. In addition, the strain can greatly affect the chemical properties of the film, leading to alternative strain relief mechanisms involving vacancy
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37

Moskalenko, V. A., R. V. Smolianets, Yu M. Pohribna, K. V. Kovtun, and S. P. Stetsenko. "Mechanisms of plastic deformation of cryorolled hafnium in the temperature range 1.7–430 K." Low Temperature Physics 50, no. 11 (2024): 1043–51. http://dx.doi.org/10.1063/10.0030444.

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The stress-strain curves of coarse-grained and nanocrystalline hafnium were found under quasi-static uniaxial compression in the temperature range 1.7–430 K. The temperature dependences of the yield strength, rate sensitivity of the deforming stress, and activation volume of the plastic deformation process were determined. The nanoscale grain size was obtained by rolling at liquid nitrogen temperature. When discussing the physical nature of the features observed below 25 K, such as the transition from smooth at room and moderately low temperatures to jump-like plastic flow, as well as the athe
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Hu, Huaxin, Xuemei Liu, Chao Hou, Haibin Wang, Fawei Tang, and Xiaoyan Song. "How hard metal becomes soft: crystallographic analysis on the mechanical behavior of ultra-coarse cemented carbide." Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials 75, no. 6 (2019): 1014–23. http://dx.doi.org/10.1107/s2052520619013118.

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Investigation into the temperature dependence of the mechanical behavior of ultra-coarse grained cemented carbide materials is highly demanded due to its service conditions of concurrent applied stress and high temperature. In the present study, based on the designed experiments and microstructural characterization combined with crystallographic analysis, the evolution of slip systems, motion and interaction of dislocations with temperature are quantified for the WC hard phase. Mechanisms are proposed for the formation of the sessile dislocations in the main slip systems at the room temperatur
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Pang, Jingyu, Zhanming Zhou, Zhengzhi Zhao, Di Tang, Juhua Liang, and Qing He. "Tensile Behavior and Deformation Mechanism of Fe-Mn-Al-C Low Density Steel with High Strength and High Plasticity." Metals 9, no. 8 (2019): 897. http://dx.doi.org/10.3390/met9080897.

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Tensile behavior and plastic deformation mechanisms of Fe-22.8Mn-8.48Al-0.86C low-density steel were studied in this thesis. After solution treatment 1100 °C for 1 h; the steels obtained an excellent combination in mechanical properties; with tensile strength of 757.4 MPa and total elongation of 68%; which were attributed to the existence of annealing twins in austenite. The present steel presented a multiple stage strain hardening behavior which was associated with the changes of such dislocation substructures. With the increase of strain, the gradual transition from tangled dislocations to d
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Sun, Baoru, and Tongde Shen. "Probing the Deformation Mechanisms of Nanocrystalline Silver by In-Situ Tension and Synchrotron X-ray Diffraction." Metals 10, no. 12 (2020): 1635. http://dx.doi.org/10.3390/met10121635.

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The mechanisms responsible for the deformation of nanocrystalline materials are not well understood although many mechanisms have been proposed. This article studies the room-temperature stress-strain relations of bulk nanocrystalline silver deformed in a tension mode at a constant strain rate. Synchrotron X-ray diffraction patterns were gathered from the deformed specimen and used to deduce such structural parameters as the grain size and the density of dislocations, twins, and stacking faults. Our quantitative results indicate that grain growth and twinning occur in the stage of elastic defo
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Li, Wenjing, Lin Xiao, Lori Walters, Greg Kasprick, and Robyn Sloan. "A Comparison Study of High-Temperature Low-Cycle Fatigue Behaviour and Deformation Mechanisms Between Incoloy 800H and Its Weldments." Journal of Nuclear Engineering 5, no. 4 (2024): 545–62. https://doi.org/10.3390/jne5040034.

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The high-temperature low-cycle fatigue (LCF) behaviour of Incoloy 800H and its weldments with Haynes 230 and Inconel 82 filler metals, which were fabricated with the gas tungsten arc welding (GTAW) technique, was investigated and compared at 760 °C. The results revealed that the Incoloy 800H weldments showed lower fatigue lifetimes compared to the base metal. However, the weldments with the Haynes 230 filler metal demonstrated an improved fatigue life at the low strain amplitude compared to both Incoloy 800H and the weldment with the Inconel 82 filler metal. The Incoloy 800H base metal showed
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Fang, Jing, Xuemei Liu, Hao Lu, Xingwei Liu, and Xiaoyan Song. "Crystal defects responsible for mechanical behaviors of a WC–Co composite at room and high temperatures – a simulation study." Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials 75, no. 2 (2019): 134–42. http://dx.doi.org/10.1107/s2052520619000295.

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The microstructure evolution and changes in the structures of crystal defects of the nanocrystalline WC–Co composite in the process of uniaxial compression were studied by simulations at both room and high temperatures. The deformation processes were demonstrated as a function of stress and temperature for the stages prior to and after yielding of the composite. The Peierls stresses were evaluated for Co and WC dislocations with increasing temperature. The deformation mechanisms for each stage of the stress–strain curve were disclosed, in which the effect of temperature was clarified. It was f
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Bi, W. B., Y. F. Wang, X. M. Zhang, et al. "The low-cyclic fatigue response and its dependence of specific surface area for open-cell nanoporous Cu." Journal of Applied Physics 133, no. 6 (2023): 065103. http://dx.doi.org/10.1063/5.0128574.

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We systematically study the low cycle fatigue behavior and its dependence of specific surface area ([Formula: see text]) for nanoporous copper (NPC) under ultrahigh strain rate ([Formula: see text] s[Formula: see text]) cyclic shear loading by conducting large-scale molecular dynamic simulation and small-angle x-ray scattering analysis. With an increase in [Formula: see text], NPC undergoes a transition from the first excellent anti-fatigue property ([Formula: see text]) to the subsequent easy-to-fatigue capacity ([Formula: see text]). Two different mechanisms are governing fatigue: (i) smooth
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Zhou, Ge, Lijia Chen, Lirong Liu, Haijian Liu, Heli Peng, and Yiping Zhong. "Low-Temperature Superplasticity and Deformation Mechanism of Ti-6Al-4V Alloy." Materials 11, no. 7 (2018): 1212. http://dx.doi.org/10.3390/ma11071212.

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The low-temperature superplastic tensile behavior and the deformation mechanisms of Ti-6Al-4V alloy are investigated in this paper. Through the experiments carried out, elongation to failure (δ) is calculated and a set of values are derived that subsequently includes the strain rate sensitivity exponent (m), deformation activation energy (Q) at low-temperature superplastic deformation, and the variation of δ, m and Q at different strain rates and temperatures. Microstructures are observed before and after superplastic deformation. The deformation mechanism maps incorporating the density of dis
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Ullmann, Madlen, Kristina Kittner, and Ulrich Prahl. "Hot Rolling of the Twin-Roll Cast and Homogenized Mg-6.8Y-2.5Zn (WZ73) Magnesium Alloy Containing LPSO Structures." Metals 11, no. 11 (2021): 1771. http://dx.doi.org/10.3390/met11111771.

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In this study, hot rolling trials were conducted on a twin-roll cast and homogenized magnesium alloy Mg-6.8Y-2.5Zn (WZ73). The WZ73 contains long period stacking ordered (LPSO) structures due to the ratio of Y and Zn content. Microstructural and texture evolution depending on the different strain and strain rates were investigated, and the resulting mechanical properties were also considered. Therefore, samples were quenched in water directly after hot rolling. The results revealed that the rolling parameters significantly influence dynamic recrystallization (DRX), while continuous and twin-in
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Carter, R. D., M. Atzmon, G. S. Was, and S. M. Bruemmer. "Deformation Mechanisms in a Proton-Irradiated Austenitic Stainless Steel." MRS Proceedings 373 (1994). http://dx.doi.org/10.1557/proc-373-171.

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AbstractSamples of austenitic 304L stainless steel have been irradiated with 3.4 MeV protons to atotal dose of 1 dpa. The microstructure of the irradiated stainless steel has been quantified by transmission electron microscopy and shown to be similar to that found in neutron-irradiated core components. Constant extension rate tensile tests have been performed at strain rates of 3x10−7 s−1 and 3x10−8 s−1 to strains of up to 27% at 23°C and 288°C. The resulting microstructures were characterized using electron and optical microscopy. Deformation of the unirradiated material is similar to that re
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Müllauer, J., and F. Appel. "Precipitation Phenomena and Strain Hardening of Intermetallic Titanium Aluminides." MRS Proceedings 753 (2002). http://dx.doi.org/10.1557/proc-753-bb5.1.

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ABSTRACTIn two-phase titanium aluminide alloys, the implementation of precipitation reactions is a widely utilized concept to control the microstructure and strengthen the material. A study has been made on the influence of carbide and boride precipitates on dislocation mobility and strengthening at 300 K. Compression tests were carried out for characterizing the mechanisms determining flow stress and dislocation glide resistance. The interaction mechanisms between the precipitates and dislocations were assessed by thermodynamic glide parameters and transmission electron microscopy. It has bee
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Stach, Eric A., U. Dahmen, and W. D. Nix. "Real Time Observations of Dislocation-Mediated Plasticity in the Epitaxial AI (011)/Si(100) Thin Film System." MRS Proceedings 619 (2000). http://dx.doi.org/10.1557/proc-619-27.

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ABSTRACTDespite numerous theoretical and experimental studies of strain relaxation in metal films on silicon substrates, the exact mechanisms by which dislocations mediate plasticity in these structures are not well understood. To elucidate these mechanisms, we present results from in-situ transmission electron microscopy annealing of thin aluminum films grown on Si (100). As a model system, we have chosen to focus on aluminum films which contain two (011) epitaxial variants with respect to the silicon substrate. In this paper we discuss our observations of the glide and climb behavior of disl
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49

Zogg, H., P. Müller, A. Fach, J. John, C. Paglino, and S. Teodoropol. "Thermal Mismatch Strain Relaxation Mechanisms and Hysteresis in Pb1−SnxSe-on-CaF2/Si Structures." MRS Proceedings 379 (1995). http://dx.doi.org/10.1557/proc-379-27.

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ABSTRACTThe strain induced by the thermal mismatch in Pbl−xSnxSe and other IV–VI compound layers on Si(111)-substrates relaxes by glide of dislocations in the main <110> {001}-glide system. The glide planes are arranged with 3-fold symmetry and inclined to the (111)-surface. Despite a high threading dislocation density (> 107 cm−2) in these heavily lattice mismatched structures, the misfit dislocations move easily even at cryogenic temperatures and after many temperature cycles between RT and 77K. The cumulative plastic deformation after these cycles is up to 500%! Despite a pronounce
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50

Atiyah, Ibrahim Abdulwahhab, Ismail Ibrahim Marhoon, and Raed Kadhim Mohammed Jawad. "An atomistic study on the strain rate and temperature dependences of the plastic deformation Cu–Au core–shell nanowires: On the role of dislocations." Journal of the Mechanical Behavior of Materials 32, no. 1 (2023). http://dx.doi.org/10.1515/jmbm-2022-0296.

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Abstract Recently, Cu–Au core–shell nanowires have been extensively used as conductors, nanocatalysts, and aerospace instruments due to their excellent thermal and electrical conductivity. In experimental studies, various methods have been presented for producing, characterizing, and strengthening these structures. However, the mechanical behavior and plastic deformation mechanisms of these materials have not been investigated at the atomic scale. Consequently, in the present study, we carried out uniaxial tensile tests on Cu–Au nanowires at various tension rates and temperatures by means of t
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