Graphene/Metal Composites Decorated with Ni Nanoclusters: Mechanical Properties.

With the developments in nanotechnology, the elaborate regulation of microstructure shows attractive potential in the design of new composite materials. Herein, composite materials composed of graphene network filled with metal nanoparticles are analyzed to optimize the fabrication process and mechanical properties. In the present work, molecular dynamic simulations are used to analyze the possibility of obtaining a composite structure with Ni-decorated graphene.

An Overview of Mechanical Properties of Diamond-like Phases under Tension.

Diamond-like phases are materials with crystal lattices very similar to diamond. Recent results suggest that diamond-like phases are superhard and superstrong materials that can be used for tribological applications or as protective coatings. In this work, 14 stable diamond-like phases based on fullerenes, carbon nanotubes, and graphene layers are studied via molecular dynamics simulation.

Effect of High-Pressure Torsion on Phase Formation and Mechanical Properties of a High-Entropy TiZrHfMoCrCo Alloy.

This investigation delved into the alterations in the mechanical properties of a TiZrHfMoCrCo high-entropy alloy due to phase transformations induced by high-pressure torsion (HPT). The alloy's genesis involved levitation melting within an argon atmosphere, presenting two distinct states for analysis: the initial, post-manufacturing state and the state subsequent to HPT treatment. The original alloy featured a composition comprising a singular A2 phase with a bcc lattice and two Laves phases, C15 and C14.

Strength and Deformation Behavior of Graphene Aerogel of Different Morphologies.

Graphene aerogels are of high interest nowadays since they have ultralow density, rich porosity, high deformability, and good adsorption. In the present work, three different morphologies of graphene aerogels with a honeycomb-like structure are considered. The strength and deformation behavior of these graphene honeycomb structures are studied by molecular dynamics simulation.

Prediction of Zn(V, Nb, Ta)N Monolayers for Optoelectronic Applications.

A new family of ternary nitride materials, Zn(V, Nb, Ta)N monolayers, is predicted. A fabrication mechanism of the Zn(V, Nb, Ta)N monolayers is proposed based on the chemical vapor deposition approach used for their bulk counterparts. The calculations show that these monolayers are thermodynamically and environmentally stable and that the ZnVN monolayer is the most stable and the easiest to synthesize.

The nitriding effect on the stability and mechanical properties of the iron titan phase: first-principles investigation.

To control the nitriding effect, which is used to enhance the mechanical properties of surfaces, a fundamental understanding of this effect is required. Modern quantum-mechanical simulation methods make it almost impossible to perform cost effective and reliable studies on the mechanisms of the influence of nitrogen on surfaces. In this work, based on density functional theory calculations, the nitriding effect on the structure and mechanical properties of titanized steel was studied using a FeTi model.

Motion of localized disturbances in scalar harmonic lattices.

We present analytical and numerical investigations of energy propagation in systems of massive particles that interact via harmonic (linear) forces. The particle motion is described by a scalar displacement, and the particles are arranged in a simple crystal lattice. For the systems under consideration we prove the conservation of the total energy flux analytically.

Mechanical Properties of the Pt-CNT Composite under Uniaxial Deformation: Tension and Compression.

Composite materials are gaining increasing attention from researchers worldwide due to their ability to offer tailored properties for various technical challenges. One of these promising fields is metal matrix composites, including carbon-reinforced metals and alloys. These materials allow for the reduction of density while simultaneously enhancing their functional properties.

Thermal Expansion and Thermal Conductivity of Ni/Graphene Composite: Molecular Dynamics Simulation.

In the present work, the thermal conductivity and thermal expansion coefficients of a new morphology of Ni/graphene composites are studied by molecular dynamics. The matrix of the considered composite is crumpled graphene, which is composed of crumpled graphene flakes of 2-4 nm size connected by van der Waals force. Pores of the crumpled graphene matrix were filled with small Ni nanoparticles.

Discrete breathers in square lattices from delocalized nonlinear vibrational modes.

Standing and moving discrete breathers (or equally, intrinsic localized modes) in a square β-Fermi-Pasta-Ulam-Tsingou lattice are obtained by applying localizing functions to the delocalized nonlinear vibrational modes (DNVMs) found earlier by Ryabov and Chechin. The initial conditions used in our study do not correspond to exact spatially localized solutions, but make it possible to obtain long-lived quasibreathers. The approach employed in this work can easily be used to search for quasibreathers in three-dimensional crystal lattices, for which DNVMs with frequencies outside the phonon spectrum are known.

Mechanical Properties of Graphene Networks under Compression: A Molecular Dynamics Simulation.

Molecular dynamics simulation is used to study and compare the mechanical properties obtained from compression and tension numerical tests of multilayered graphene with an increased interlayer distance. The multilayer graphene with an interlayer distance two-times larger than in graphite is studied first under biaxial compression and then under uniaxial tension along three different axes. The mechanical properties, e.

Metal/Graphene Composites: A Review on the Simulation of Fabrication and Study of Mechanical Properties.

Although carbon materials, particularly graphene and carbon nanotubes, are widely used to reinforce metal matrix composites, understanding the fabrication process and connection between morphology and mechanical properties is still not understood well. This review discusses the relevant literature concerning the simulation of graphene/metal composites and their mechanical properties. This review demonstrates the promising role of simulation of composite fabrication and their properties.

Effects of Severe Plastic Deformation and Ultrasonic Treatment on the Structure, Strength, and Corrosion Resistance of Mg-Al-Zn Alloy.

Nowadays, there is a great demand for increasing the strength and corrosion resistance of magnesium alloys for their wider use in machine engineering, oil industry, and medicine. This paper is devoted to a study on the effects of the combined process of reduction and equal channel angular pressing, as well as the subsequent ultrasonic irradiation on the structure, strength, and corrosion properties of the Mg-Al-Zn alloy. Deformation processing results in an increase of the strength up to 280 ± 10 MPa.

Modulational Instability of Delocalized Modes in fcc Copper.

Delocalized nonlinear vibrational modes (DNVMs) are exact solutions of the equations of motion, and therefore, DNVMs exist at any vibration amplitude and do not depend on interaction potentials. For the first time, modulation instability of four one-component three-dimensional DNVMs is studied in a single crystal of fcc copper with the use of methods of molecular dynamics. DNVMs frequencies, evolution of stresses, kinetic and potential energies, and heat capacity depending on the oscillation amplitudes are analyzed.

Mechanical Properties of Cubene Crystals.

The fullerene family, whose most popular members are the spherical C60 and C70 molecules, has recently added a new member, the cube-shaped carbon molecule C8 called a cubene. A molecular crystal based on fullerenes is called fullerite. In this work, based on relaxational molecular dynamics, two fullerites based on cubenes are described for the first time, one of which belongs to the cubic system, and the other to the triclinic system.

Methodologyfor Molecular Dynamics Simulation of Plastic Deformation of a Nickel/Graphene Composite.

In this study, some features of molecular dynamics simulation for evaluating the mechanical properties of a Ni/graphene composite and analyzing the effect of incremental and dynamic tensile loading on its deformation are discussed. A new structural type of the composites is considered: graphene network (matrix) with metal nanoparticles inside. Two important factors affecting the process of uniaxial tension are studied: tension strain rate (5 ×10-3 ps-1 and 5 ×10-4 ps-1) and simulation temperature (0 and 300 K).

Discrete dislocation simulation of the ultrasonic relaxation of non-equilibrium grain boundaries in a deformed polycrystal.

For the first time, the relaxation of disordered dislocation arrays in a model 3 × 3 columnar polycrystal under ultrasonic action is studied using the discrete dislocation approach. All grains contain three non-parallel slip systems located at an angle of 60° to each other. The non-equilibrium state of the grain boundaries is modeled using two finite edge dislocation walls with Burgers vector of opposite signs, which are equivalent to a wedge junction disclination quadrupole.

Effect of Nanoparticle Size on the Mechanical Strength of Ni-Graphene Composites.

The effect of the size of nickel nanoparticles on the fabrication of a Ni-graphene composite by hydrostatic pressure at 0 K followed by annealing at 1000 and 2000 K is studied by molecular dynamics simulation. Crumpled graphene, consisting of crumpled graphene flakes interconnected by van der Waals forces is chosen as the matrix for the composite and filled with nickel nanoparticles composed of 21 and 47 atoms. It is found that the main factors that affect composite fabrication are nanoparticle size, the orientation of the structural units, and temperature of the fabrication process.

Discrete breathers in a triangular β-Fermi-Pasta-Ulam-Tsingou lattice.

A practical approach to the search for (quasi-) discrete breathers (DBs) in a triangular β-FPUT lattice (after Fermi, Pasta, Ulam, and Tsingou) is proposed. DBs are obtained by superimposing localizing functions on delocalized nonlinear vibrational modes (DNVMs) having frequencies above the phonon spectrum of the lattice. Zero-dimensional and one-dimensional DBs are obtained.

Crumpled Graphene-Storage Media for Hydrogen and Metal Nanoclusters.

Understanding the structural behavior of graphene flake, which is the structural unit of bulk crumpled graphene, is of high importance, especially when it is in contact with the other types of atoms. In the present work, crumpled graphene is considered as storage media for two types of nanoclusters-nickel and hydrogen. Crumpled graphene consists of crumpled graphene flakes bonded by weak van der Waals forces and can be considered an excellent container for different atoms.

First-Principles Prediction of Two-Dimensional BCP and BCP: Structural Stability, Fundamental Properties, and Renewable Energy Applications.

The existence of two novel hybrid two-dimensional (2D) monolayers, 2D BCP and 2D BCP, has been predicted based on the density functional theory calculations. It has been shown that these materials possess structural and thermodynamic stability. 2D BCP is a moderate band gap semiconductor, while 2D BCP is a zero band gap semiconductor.

The Effect of Pre-Annealing on the Evolution of the Microstructure and Mechanical Behavior of Aluminum Processed by a Novel SPD Method.

A novel continuous process of severe plastic deformation (SPD) named continuous close die forging (CCDF) is presented. The CCDF process combines all favorite advances of multidirectional forging and other SPD methods, and it can be easily scaled up for industrial use. Keeping constant both the cross section and the length of the sample, the new method promotes a refinement of the microstructure.

Chain Model for Carbon Nanotube Bundle under Plane Strain Conditions.

Carbon nanotubes (CNTs) have record high tensile strength and Young's modulus, which makes them ideal for making super strong yarns, ropes, fillers for composites, solid lubricants, etc. The mechanical properties of CNT bundles have been addressed in a number of experimental and theoretical studies. The development of efficient computational methods for solving this problem is an important step in the design of new CNT-based materials.

A First-Principles Study on the Adsorption of Small Molecules on Arsenene: Comparison of Oxidation Kinetics in Arsenene, Antimonene, Phosphorene, and InSe.

Arsenene, a new group-V two-dimensional (2D) semiconducting material beyond phosphorene and antimonene, has recently gained an increasing attention owning to its various interesting properties which can be altered or intentionally functionalized by chemical reactions with various molecules. This work provides a systematic study on the interactions of arsenene with the small molecules, including H , NH , O , H O, NO, and NO . It is predicted that O , H O, NO, and NO are strong acceptors, while NH serves as a donor.

Mass transfer in the Frenkel-Kontorova chain initiated by molecule impact.

The Frenkel-Kontorova chain with a free end is used to study initiation and propagation of crowdions (antikinks) caused by impact of a molecule consisting of K atoms. It is found that molecules with 1 View Article and Find Full Text PDF