scholarly journals How Atoms of Polycrystalline Nb 20.6 Mo 21.7 Ta 15.6 W 21.1 V 21.0 refractory High-Entropy Alloys Rearrange during the Melting Process

2021 ◽  
Author(s):  
Shin-Pon Ju ◽  
Chen-Chun Li
Keyword(s):  
Molecular Dynamics ◽  
Melting Point ◽  
Single Crystal ◽  
Melting Temperature ◽  
Md Simulation ◽  
Melting Process ◽  
Structural Rearrangement ◽  
High Entropy Alloys ◽  
High Entropy ◽  
Melting Mechanism

Abstract The melting mechanism of single crystal and polycrystalline Nb 20.6 Mo 21.7 Ta 15.6 W 21.1 V 21.0 RHEAs was investigated by the molecular dynamics (MD) simulation using the 2NN MEAM potential. For the single crystal RHEA, the density profile displays an abrupt drop from 11.25 to 11.00 g/cm 3 at temperatures from 2910 to 2940 K, indicating all atoms begin significant local structural rearrangement. For polycrystalline RHEAs, a two-stage melting process is found. In the first melting stage, the melting of the grain boundary (GB) regions firstly occurs at the pre-melting temperature, which is relatively lower than the corresponding system-melting point. At the pre-melting temperature, most GB atoms have enough kinetic energies to leave their equilibrium positions, and then gradually induce the rearrangement of grain atoms close to GB. In the second melting stage at the melting point, most grain atoms have enough kinetic energies to rearrange, resulting in the chemical short-ranged order (CSRO) changes of all pairs.

Microstructure of Nanoceramic during Sintering and Preparation

2010 ◽  
Vol 105-106 ◽  
pp. 90-93 ◽  
Author(s):  
Ju Ping Ren ◽  
Ke Zhang ◽  
Yu Lan Tang
Keyword(s):  
Molecular Dynamics ◽  
Correlation Function ◽  
Melting Point ◽  
Md Simulation ◽  
3D Model ◽  
Rapid Heating ◽  
Pair Correlation ◽  
Melting Process ◽  
Energy Evolution ◽  
Heating Up

The microstructure evolution during sintering and preparation of nanoceramic materials is studied by molecular dynamics (MD) simulation. A 3D model for nanoceramic crystal body including mainly crystal planes of (100) and (110) is developed. This model is used to simulate the hot pressing of nanoceramic, especially for SiC, by rapid heating-up and cooling-down under certain pressure. In this model, the Tersoff potential function is used to simulate the interatomic force between atoms. The microstructure during melting process and crystallizing process are investigated by analyzing energy evolution, pair correlation function and the graph of instantaneous place of the atoms. The results show that the microstructure is amorphous after melting, and crystal planes of (100) and (110) are different in density, melting point and microstructure, showing anisotropy.

scholarly journals Liquid Phase Separation in Ag-Co-Cr-Fe-Mn-Ni, Co Cr-Cu-Fe-Mn-Ni and Co-Cr-Cu-Fe-Mn-Ni-B High Entropy Alloys for Biomedical Application

Crystals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 527 ◽  
Author(s):  
Takeshi Nagase ◽  
Mitsuharu Todai ◽  
Takayoshi Nakano
Keyword(s):  
Phase Separation ◽  
Liquid Phase ◽  
Biomedical Application ◽  
Melting Process ◽  
Liquid Phase Separation ◽  
Heat Of Mixing ◽  
High Entropy Alloys ◽  
High Entropy ◽  
Metallic Biomaterials ◽  
Fundamental Research

The liquid phase separation (LPS) behavior in Co-Cr-based high-entropy alloys (HEAs) is an important target for the development of Co-Cr-based HEAs for metallic biomaterials (BioHEAs). The solidification microstructure in Ag-Co-Cr-Fe-Mn-Ni-Ag, Co-Cr-Cu-Fe-Mn-Ni-Cu, and Co-Cr-Cu-Fe-Mn-Ni-B HEAs, which were designed as the combination of the equiatomic CoCrFeMnNi with Ag, Cu, and the interstitial element of B, was investigated as the fundamental research of LPS in Co-Cr-based HEAs. Ingots of equiatomic AgCoCrFeMnNi, equiatomic CoCrCuFeMnNi, non-equiatomic CoCrCuxFeMnNi (x = 2, 3), and CoCrCuxFeMnNiB0.2 (x = 1, 2, 3) with a small amount of B were fabricated using the arc-melting process. A macroscopic phase-separated structure was observed in the ingots of the equiatomic AgCoCrFeMnNi and CoCrCuxFeMnNiB0.2 (x = 2, 3) HEAs. The addition of a small amount of B enhanced the LPS tendency in the Co-Cr-Fe-Mn-Ni-Cu HEAs. The LPS behavior was discussed through the heat of mixing and computer coupling of phase diagrams and thermochemistry (CALPHAD).

scholarly journals Molecular Dynamics Studies of the Melting of Copper with Vacancies amd Dislocations at High Pressures

MRS Advances ◽  
2017 ◽  
Vol 2 (48) ◽  
pp. 2597-2602 ◽  
Author(s):  
Clarence C Matthai ◽  
Jessica Rainbow
Keyword(s):  
Molecular Dynamics ◽  
Melting Temperature ◽  
Large Scale ◽  
High Pressures ◽  
Defect Density ◽  
Melting Process ◽  
Interatomic Potentials ◽  
Embedded Atom ◽  
Line Defects ◽  
Dynamics Simulations

ABSTRACTMolecular dynamics simulations of the melting process of bulk copper were performed using the Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS) with the interatomic potentials being described by the embedded atom method. The aim of the study was to understand the effects of high pressures and defects on the melting temperature. The simulations were visualised using Visual Molecular Dynamics (VMD). The melting temperature of a perfect copper crystal, was found to be slightly higher than the experimentally observed value. The melting temperature as a function of pressure was determined and compared with experiment. Point and line defects, in the form of dislocations, were then introduced into crystal and the new melting temperature of the crystal determined. We find that the melting temperature decreases as the defect density is increased. Additionally, the slope of the melting temperature curve was found to decrease as the pressure was increased while the vacancy formation energy increases with pressure.

scholarly journals Atomic-scale characterization of occurring phenomena during hot nanometric cutting of single crystal 3C–SiC

RSC Advances ◽  
2016 ◽  
Vol 6 (75) ◽  
pp. 71409-71424 ◽  
Author(s):  
Saeed Zare Chavoshi ◽  
Xichun Luo
Keyword(s):  
Molecular Dynamics ◽  
Single Crystal ◽  
Md Simulation ◽  
Atomic Scale ◽  
Nanometric Cutting ◽  
Crystal Orientations ◽  
Scale Characterization

Nanometric cutting of single crystal 3C–SiC on the three principal crystal orientations at various cutting temperatures spanning from 300 K to 3000 K was investigated by the use of molecular dynamics (MD) simulation.

Effects of stacking fault energy on the deformation behavior of CoNiCrFeMn high-entropy alloys: A molecular dynamics study

2021 ◽  
Vol 119 (20) ◽  
pp. 201907
Author(s):  
Tengfei Zheng ◽  
Jiecheng Lv ◽  
Yuan Wu ◽  
Hong-Hui Wu ◽  
Shaofei Liu ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Deformation Behavior ◽  
Stacking Fault ◽  
Stacking Fault Energy ◽  
High Entropy Alloys ◽  
High Entropy

Melting temperature of CoCrFeNiMn high-entropy alloys

2018 ◽  
Vol 148 ◽  
pp. 69-75 ◽  
Author(s):  
M.A. Gutierrez ◽  
G.D. Rodriguez ◽  
G. Bozzolo ◽  
H.O. Mosca
Keyword(s):  
Melting Temperature ◽  
High Entropy Alloys ◽  
High Entropy

Molecular Dynamics Study on the Diffusion Process of AuAgCuNiPd High-entropy Alloy Metallurgy Induced by Pulsed Laser Heating

2021 ◽  
Author(s):  
Gen Lin ◽  
Jianwu Guo ◽  
Pengfei Ji
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Laser Heating ◽  
Pulsed Laser ◽  
High Entropy Alloy ◽  
High Entropy Alloys ◽  
High Entropy ◽  
Alloy Material ◽  
Wide Range ◽  
Pulsed Laser Heating

As a novel alloy material with outstanding mechanical properties, high-entropy alloys have a wide range of promising applications. By establishing individual Au, Ag, Cu, Ni, and Pd nanolaminates with faced-centered-cubic...

Sign in / Sign up

Export Citation Format

Share Document