Nanoscale origin of the crystalline-to-amorphous phase transformation and damage tolerance of Cantor alloys at cryogenic temperatures

2022 ◽  
pp. 117639
Author(s):  
Weiming Ji ◽  
Mao See Wu
Keyword(s):  
Phase Transformation ◽  
Amorphous Phase ◽  
Damage Tolerance ◽  
Cryogenic Temperatures

scholarly journals Effects of temperatures on pressure-induced structural changes in amorphous Si: A molecular-dynamics study

10.29007/6kp3 ◽  
2020 ◽  
Author(s):  
Renji Mukuno ◽  
Manabu Ishimaru
Keyword(s):  
Molecular Dynamics ◽  
Phase Transformation ◽  
Amorphous Phase ◽  
Structural Changes ◽  
Interatomic Potential ◽  
Activation Barrier ◽  
Distribution Functions ◽  
High Density ◽  
Angle Distribution ◽  
Dynamics Simulations

The structural changes of amorphous silicon (a-Si) under compressive pressure were examined by molecular-dynamics simulations using the Tersoff interatomic potential. a-Si prepared by melt-quenching methods was pressurized up to 30 GPa under different temperatures (300K and 500K). The density of a-Si increased from 2.26 to 3.24 g/cm3 with pressure, suggesting the occurrence of the low-density to high-density amorphous phase transformation. This phase transformation occurred at the lower pressure with increasing the temperature because the activation barrier for amorphous-to-amorphous phase transformation could be exceeded by thermal energy. The coordination number increased with pressure and time, and it was saturated at different values depending on the pressure. This suggested the existence of different metastable atomic configurations in a-Si. Atomic pair-distribution functions and bond-angle distribution functions suggested that the short-range ordered structure of high-density a-Si is similar to the structure of the high-pressure phase of crystalline Si (β-tin and Imma structures).

Analysis of damage-tolerance of TRIP-assisted V10Cr10Fe45Co30Ni5 high-entropy alloy at room and cryogenic temperatures

2020 ◽  
Vol 844 ◽  
pp. 156090 ◽  
Author(s):  
Yong Hee Jo ◽  
Junha Yang ◽  
Kyung-Yeon Doh ◽  
Woojin An ◽  
Dae Woong Kim ◽  
...  
Keyword(s):  
Damage Tolerance ◽  
High Entropy Alloy ◽  
Cryogenic Temperatures ◽  
High Entropy

Study on Nanometric Machining Mechanism of Monocrystalline Silicon by Molecular Dynamics

2011 ◽  
Vol 393-395 ◽  
pp. 1475-1478
Author(s):  
Hong Guo
Keyword(s):  
Molecular Dynamics ◽  
Phase Transformation ◽  
Potential Function ◽  
Amorphous Phase ◽  
Cutting Forces ◽  
Elastic Recovery ◽  
Monocrystalline Silicon ◽  
Three Dimensional Model ◽  
Cutting Mechanism ◽  
Nanometric Cutting

A three-dimensional model of molecular dynamics (MD) was employed to study the nanometric cutting mechanism of monocrystalline silicon. The model included the utilization of the Morse potential function to simulate the interatomic force between the workpiece and the tool, and the Tersoff potential function between silicon atoms. Amorphous phase transformation and chip volume change are observed by analyses of the snapshots of the MD simulation of the nanometric cutting process, energy and cutting forces. Dislocations and elastic recovery in the deformed region around the tool do not appear. Cutting forces initiate the amorphous phase transformation, and thrust forces play an important role in driving the further transformation development. Nanometric cutting mechanism of monocrystalline silicon is not the plastic deformation involving the generation and propagation of dislocations, but deformation via amorphous phase transformation.

Sign in / Sign up

Export Citation Format

Share Document