Deformation behaviour of Cu and Cu–Al in the dislocation starved regime: A molecular dynamics study

2022 ◽  
Vol 203 ◽  
pp. 111087
Author(s):  
G. Kamalakshi ◽  
Prita Pant ◽  
M.P. Gururajan
2019 ◽  
Vol 2019 ◽  
pp. 1-5 ◽  
Author(s):  
S. K. Joshi ◽  
Kailash Pandey ◽  
Sanjeev K. Singh ◽  
Santosh Dubey

Metallic nanowires show great potential for applications in miniaturization of electronic devices due to their extraordinary mechanical strength and electrical properties. Experimental investigations of these properties are difficult due to their size and complications in performing experiments at such length scales. Computational techniques based on classical molecular dynamics simulations (using LAMMPS) provide an effective mean to understand the mechanical deformation behaviour of such nanowires with considerable accuracy and predictability. In the present investigation, we have discussed the deformation behaviour of Au nanowires due to tensile loading using classical molecular dynamics simulations (LAMMPS). The effect of strain rate and temperature on the yield strength of the nanowire has been studied in detail. The deformation mechanisms have also been discussed.


2020 ◽  
Vol 978 ◽  
pp. 428-435
Author(s):  
Krishna Chaitanya Katakam ◽  
Natraj Yedla

The mechanical properties and deformation mechanism of nickel nanowire of dimension 100 Å (x-axis) × 1000 Å (y-axis) × 100 Å (z-axis) containing a single linear surface defect is studied at different temperatures using molecular dynamics simulations. The defect is created by deleting a row of atoms on the surface and is inclined at 25° to the loading axis. The tensile test is carried out at 0.01 K, 10 K, 100 K and 300 K temperature and 108 s-1strain rate. To determine the effect of temperature on the stress-strain curves, fracture and failure mechanism, a thorough investigation has taken place. Maximum strength of 21.26 GPa is observed for NW deformed at 0.01 K temperature and the strength decreased with increase in temperature. Through slip lines, the deformation relief pattern taken place by developing the extrusion areas along with intrusion over the surface defect area in all NWs deformed at respective temperatures. Further it is observed that fracture strains decrease with increase in temperature. After yielding, stacking faults associated with dislocations are generated by slip on all four {111} planes. Different type of dislocations with both intrinsic and extrinsic stacking faults are noticed. Out of all dislocation densities, Shockley partial dislocation densities has recorded a maximum value.


Crystals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 366 ◽  
Author(s):  
G. Sainath ◽  
Sunil Goyal ◽  
A. Nagesha

The deformation behaviour of twinned FCC nanowires has been extensively investigated in recent years. However, the same is not true for their BCC counterparts. Very few studies exist concerning the deformation behaviour of twinned BCC nanowires. In view of this, molecular dynamics (MD) simulations have been performed to understand the deformation mechanisms in twinned BCC Fe nanowires. The twin boundaries (TBs) were oriented parallel to the loading direction [110] and the number of TBs is varied from one to three. MD simulation results indicate that deformation under the compressive loading of twinned BCC Fe nanowires is dominated by a unique de-twinning mechanism involving the migration of a special twin–twin junction. This de-twinning mechanism results in the complete annihilation of pre-existing TBs along with reorientation of the nanowire. Further, it has been observed that the annihilation of pre-existing TBs has occurred through two different mechanisms, one without any resolved shear stress and other with finite and small resolved shear stress. The present study enhances our understanding of de-twinning in BCC nanowires.


2000 ◽  
Vol 634 ◽  
Author(s):  
P. M. Derlet ◽  
H. Van Swygenhoven

ABSTRACTFormer molecular dynamics computer simulations of polycrystalline Ni and Cu metals with mean grain sizes ranging between 3 and 12 nm demonstrated a change in deformation mechanism as a function of grain size: at the smallest grain sizes all deformation is accommodated in the grain boundaries. In this paper we report on the influence of the presence of two free surfaces on the deformation behaviour. The purpose of this simulation is to study which phenomena observed in in-situ tensile experiments performed in the electron microscope can be expected to be intrinsic properties of the deformation process and which phenomena are due to the presence of two free surfaces separated by a very small distance.


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