Effect of void size and Mg contents on plastic deformation behaviors of Al-Mg alloy with pre-existing void: Molecular dynamics study

2022 ◽  
Author(s):  
Ning Wei ◽  
Ai-Qiang Shi ◽  
Zhi-Hui Li ◽  
Bing-Xian Ou ◽  
Si-Han Zhao ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Plastic Deformation ◽  
Yield Stress ◽  
Stacking Faults ◽  
Mg Alloy ◽  
Void Size ◽  
Plastic Mechanism ◽  
Deformation Properties ◽  
Eam Potential ◽  
Mg Content

Abstract The plastic deformation properties of cylindrical pre-void Aluminum-Magnesium (Al-Mg) alloy under uniaxial tension are explored using molecular dynamics simulations with embedded atom method (EAM) potential. The factors of Mg content, void size, and temperature are considered. The results show that the void fraction decreases with increasing Mg in the plastic deformation, and it is almost independent of Mg content when Mg is beyond 5%. Both Mg contents and stacking faults around the void affect the void growth. These phenomena are explained by the dislocation density of the sample and stacking faults distribution around the void. The variation trends of yield stress caused by void size are in good agreement with Lubarda model. Moreover, temperature effects are explored, the yield stress and Young's modulus obviously decrease with temperature. Our results may enrich and facilitate the understanding of the plastic mechanism of Al-Mg with defects or other alloys.

scholarly journals The Effects of Grain Boundary Misorientation on the Mechanical Properties and Mechanism of Plastic Deformation of Ni/Ni3Al: A Molecular Dynamics Study

Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5715
Author(s):  
Jun Ding ◽  
Sheng-Lai Zhang ◽  
Quan Tong ◽  
Lu-Sheng Wang ◽  
Xia Huang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Plastic Deformation ◽  
Grain Boundary ◽  
Misorientation Angle ◽  
Interfacial Energy ◽  
Stacking Faults ◽  
Boundary Misorientation ◽  
Grain Boundary Misorientation ◽  
Mechanisms Of Plastic Deformation

The effects of grain boundary misorientation angle (θ) on mechanical properties and the mechanism of plastic deformation of the Ni/Ni3Al interface under tensile loading were investigated using molecular dynamics simulations. The results show that the space lattice arrangement at the interface is dependent on grain boundary misorientations, while the interfacial energy is dependent on the arrangement. The interfacial energy varies in a W pattern as the grain boundary misorientation increases from 0° to 90°. Specifically, the interfacial energy first decreases and then increases in both segments of 0–60° and 60–90°. The yield strength, elastic modulus, and mean flow stress decrease as the interfacial energy increases. The mechanism of plastic deformation varies as the grain boundary misorientation angle (θ) increases from 0° to 90°. When θ = 0°, the microscopic plastic deformation mechanisms of the Ni and Ni3Al layers are both dominated by stacking faults induced by Shockley dislocations. When θ = 30°, 60°, and 80°, the mechanisms of plastic deformation of the Ni and Ni3Al layers are the decomposition of stacking faults into twin grain boundaries caused by extended dislocations and the proliferation of stacking faults, respectively. When θ = 90°, the mechanisms of plastic deformation of both the Ni and Ni3Al layers are dominated by twinning area growth resulting from extended dislocations.

Computer Simulation of Tensile Deformation of Titanium Small Single Crystals with Stacking Faults

1993 ◽  
Vol 319 ◽  
Author(s):  
M. Aoshima ◽  
T. Kusube ◽  
J. Ida ◽  
Masao Doyama
Keyword(s):  
Molecular Dynamics ◽  
Computer Simulation ◽  
Single Crystals ◽  
Yield Stress ◽  
Tensile Deformation ◽  
Tensile Axis ◽  
Stacking Faults ◽  
Stacking Fault ◽  
Molecular Dynamics Method ◽  
Dynamics Method

AbstractSmall single crystals of titanium with and without stacking faults have been pulled by use of the molecular dynamics method. The tensile axis was [0001] and the stacking fault was introduced on (0001) pianes. The yield stress was higher in the crystal with stacking faults. The deformation was complicated in the crystal with stacking fault. Dislocations were created near the tip of a crack and moved on (1122).

The Relationship between Mg Content and Extra-Hardening in Ultrafine Grained Al-Mg Alloy by SPD

2018 ◽  
Vol 941 ◽  
pp. 1173-1177
Author(s):  
Yuto Suzuki ◽  
Yuichi Shiono ◽  
Taiki Morishige ◽  
Toshihide Takenaka
Keyword(s):  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Work Hardening ◽  
Stacking Fault ◽  
Stacking Fault Energy ◽  
Mg Alloy ◽  
Al Alloy ◽  
Ultrafine Grained ◽  
Mg Content ◽  
The Relationship

Severe Plastic Deformation (SPD) process is one of methods for obtaining UFG-Al. It was reported in SPD-processed Al alloy that the extra-hardening due to work hardening caused by accumulated dislocation in the grains. In Al-Mg alloy, Mg decreases the stacking fault energy in this alloy, and dislocation tends to accumulate in the grains. In this study, Al-Mg alloy with various Mg contents were processed by Equal-Channel Angular Pressed (ECAP) which was one of SPD and annealed after processed ECAP. The relationship between Mg content and magnitude of extra-hardening was investigated. In ECAPed Al-3mass%Mg alloy, it was thought that extra-hardening was caused. Magnitude of extra-hardening was increased with increasing Mg content.

Cascade Overlap in hcp Zirconium: Defect Accumulation and Microstructure Evolution with Radiation using Molecular Dynamics Simulations

2013 ◽  
Vol 1514 ◽  
pp. 37-42 ◽  
Author(s):  
Prithwish K. Nandi ◽  
Jacob Eapen
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Microstructure Evolution ◽  
Stacking Faults ◽  
Embedded Atom Method ◽  
Shockley Partial Dislocation ◽  
Embedded Atom ◽  
Defect Accumulation ◽  
Dynamics Simulations ◽  
Eam Potential

ABSTRACTMolecular dynamics simulations are performed to investigate the defect accumulation and microstructure evolution in hcp zirconium (Zr) – a material which is widely used as clad for nuclear fuel. Cascades are generated with a 3 keV primary knock-on atom (PKA) using an embedded atom method (EAM) potential with interactions modified for distances shorter than 0.1 Å. With sequential cascade simulations we show the emergence of stacking faults both in the basal and prism planes, and a Shockley partial dislocation on the basal plane.

Twinning Deformation in Martensite Microstructure

1999 ◽  
Vol 578 ◽  
Author(s):  
G.J. Ackland ◽  
U. Pinsook
Keyword(s):  
Molecular Dynamics ◽  
Shear Strain ◽  
Yield Stress ◽  
Stacking Faults ◽  
Strain Curve ◽  
Stress Strain Curve ◽  
Yield Strain ◽  
Twin Boundaries ◽  
Stick Slip ◽  
Martensite Microstructure

AbstractMolecular dynamics is used to study twinning deformation in a martensite microstructure obtained from rapid cooling β zirconium through the bcc-hcp transition. The microstructure is composed of (1011) twin boundaries and boundary dislocations which sometimes spread across the twins to form stacking faults. A series of such equilibrium microstructures subjected to discrete, increasing < 1012 > (1011) shear strain. The stress-strain curve has stick-slip behaviour with yield stress of ≈ 5.OKbar and yield strain of ≈ 3.8%. Deformation occurs through movement of twin boundaries in segments between boundary dislocations. Straight perfect twin boundaries do not move.

Molecular dynamics simulations of the effect of temperature and strain rate on the plastic deformation of body centred cubic iron nanowires

2021 ◽  
pp. 1-19
Author(s):  
Qian Wu ◽  
Yong Wang ◽  
Tao Han ◽  
Hongtao Wang ◽  
Laihui Han ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Plastic Deformation ◽  
Strain Rate ◽  
Yield Stress ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Strain Curve ◽  
Dislocation Slip ◽  
Stress Strain Curve ◽  
Stress Strain

Abstract The tensile tests of BCC Fe nanowires were simulated through molecular dynamics methods. The temperature and strain rate effects on the mechanical properties as well as the orientation-dependent plastic deformation mechanism were analyzed. For [001]-oriented BCC Fe nanowires, as the temperature increased, the yield stress and Young's modulus decreased. While the yield stress and Young's modulus increased as the strain rate increased. With the increase of temperature, when the temperature was less than 400 K, the twin propagation stress decreased dramatically, and then tended to reach a saturation value at higher temperatures. Under different temperatures and strain rates, the [001]-oriented Fe nanowires all deformed by twinning. The oscillation stage in the stress-strain curve corresponds to the process from the nucleation of the twin to the reorientation of the nanowire. For [110]-oriented Fe nanowires, the plastic deformation is dominated by dislocation slip. The independent events such as the nucleation, slip, and annihilation of dislocations are the causes of the unsteady fluctuations in the stress-strain curve. The Fe nanowires eventually undergo shear damage along the dominant slip surface.

Deformation Twins and Stacking Faults in an AA5182 Al-Mg Alloy Processed by High Pressure Torsion

2008 ◽  
Vol 579 ◽  
pp. 147-154 ◽  
Author(s):  
M. Liu ◽  
Hans Jørgen Roven ◽  
Maxim Yu. Murashkin ◽  
Ruslan Valiev
Keyword(s):  
Molecular Dynamics ◽  
High Pressure ◽  
Molecular Dynamics Simulations ◽  
Grain Boundaries ◽  
High Pressure Torsion ◽  
Stacking Faults ◽  
Pure Metal ◽  
Mg Alloy ◽  
Transmission Electron ◽  
Dynamics Simulations

High-resolution transmission electron microscopy investigations revealed different types of deformation structures in a nanostructured commercial Al–Mg alloy processed by high pressure torsion at room temperature. Microtwins and stacking faults were detected within both nanocrystalline grains and ultrafine grains. Full dislocations in the form of dipoles were observed within grains and near the grain boundaries. Two twinning mechanisms previously predicted by molecular-dynamics simulations were directly verified including the heterogeneous twins nucleated by the successive emission of Shockley partials from grain boundaries and homogeneous twins formed in the grain interiors by the dynamic overlapping of stacking faults. Hence, the formation of full dislocations, stacking faults and twins in the present aluminum alloy subjected to severe plastic deformation may be interpreted in terms of molecular-dynamics simulations based on generalized planar fault energy curves for pure metal systems.

Simulation of Tensile Deformation of Small Copper Single Crystals

1992 ◽  
Vol 291 ◽  
Author(s):  
Masao Doyama
Keyword(s):  
Molecular Dynamics ◽  
Plastic Deformation ◽  
Single Crystals ◽  
Yield Stress ◽  
Tensile Deformation ◽  
Molecular Dynamics Method ◽  
Copper Single Crystals ◽  
Dynamics Method

ABSTRACTThe molecular dynamics method was used to simulate the plastic deformation of small copper single crystals. Dislocations were created near the tips of cracks. A very sharp yield stress was found.

MOLECULAR DYNAMICS STUDY OF THE INTERFACE-STRUCTURE FORMATION OF A COPPER/SILVER BILAYER

2011 ◽  
Vol 03 (01n02) ◽  
pp. 23-38 ◽  
Author(s):  
Z. H. XU ◽  
L. YUAN ◽  
D. B. SHAN ◽  
B. GUO ◽  
H. S. DONG ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Stacking Faults ◽  
Interface Structure ◽  
Partial Dislocations ◽  
Cu Film ◽  
Layer Mode ◽  
Dynamics Simulations ◽  
Ag Substrate ◽  
Eam Potential ◽  
Curved Interface

The formation of the interface of a Cu/Ag bilayer during sputtering was studied with molecular dynamics simulations with EAM potential. The results show that the first deposited Ag layer grows on the Cu substrate by the layer mode, while the first deposited Cu layer grows on the Ag substrate by the island mode for both the (111) and (001) orientated growth. The film is epitaxial up to the coverage, reaching about 10 monolayers except for Cu growth on Ag (001). Ag atoms in the (001) orientated substrate diffuse into the Cu film for a longer distance compared to other cases. The interface is sharp and exhibits a (9 × 9) superstructure with hexagonal moiré pattern for both Ag growth on Cu (111) and Cu growth on Ag (111). The displacement of the superposed Cu atoms contributes to the corrugation of the interface for both cases. A c(10 × 2) superstructure forms when Ag grows on Cu (001). When Cu is deposited on Ag (001), partial dislocations are activated near the interface, and a great number of stacking faults form in the Cu film with the significantly curved interface.

Effect of Vanadium on Plastic Deformation in Llo TiAl Compound Alloys

1988 ◽  
Vol 133 ◽  
Author(s):  
Sung H. Whang ◽  
Yoo-Dong Hahn
Keyword(s):  
Plastic Deformation ◽  
Yield Stress ◽  
Uniaxial Compression ◽  
Fracture Stress ◽  
Room Temperature ◽  
Stacking Faults ◽  
Aluminum Concentration ◽  
Stress And Strain ◽  
Thin Foils ◽  
Miniature Specimens

ABSTRACTTernary Ti-Al-V (Llo) alloys containing vanadium up to 10 at.% and aluminum in the range of 50–55 at.% were prepared. Miniature specimens machined from these alloys were deformed in uniaxial compression at room temperature.The yield stress, and fracture stress and strain were determined with respect to vanadium and aluminum concentration. The deformed alloys were electropolished into thin foils and studied by TEM. In particular, the types of dislocations, stacking faults and twins in the Ti-Al-V alloys were investigated by TEM.

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