Atomistic simulations to study crack tip behaviour in multi-elemental alloys

•Atomistic simulations to study crack tip behavior in multi-elemental alloys.•Orientation of crack plane switches the deformation governing mechanism.•Perfect plastic conditions prevail in medium and high entropy alloys.•Dislocations and stacking faults govern deformation in high entropy alloys. The...

Full description

Saved in:
Bibliographic Details
Published in:Engineering fracture mechanics 2021-02, Vol.243, p.107536, Article 107536
Main Authors: Kumar Singh, Sandeep, Parashar, Avinash
Format: Article
Language:English
Subjects:
Alloying elements
Alloys
Configuration management
Crack propagation
Crack tips
Crystal dislocations
Crystal structure
Dislocation density
Entropy
Face centered cubic lattice
High entropy alloys
Molecular dynamics
Propagation modes
Quaternary alloys
Quinary systems
Secondary dislocations
Simulation
Stacking faults
Twinning
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:•Atomistic simulations to study crack tip behavior in multi-elemental alloys.•Orientation of crack plane switches the deformation governing mechanism.•Perfect plastic conditions prevail in medium and high entropy alloys.•Dislocations and stacking faults govern deformation in high entropy alloys. The aim of the article is to study the crack tip behaviour in mutli-elemental alloys. Molecular dynamics based simulations were performed in conjunction with 2NN MEAM potential to study the fracture behaviour in ternary, quaternary, and quinary alloy configurations. Simulations were performed after aligning the crack plane with three different principle planes of FCC crystal. Deformation in each of the orientations was primarily governed by dislocations, twinning, and stacking faults emanating front the crack tips or from the surface of the crack plane. Medium and high entropy alloys have shown higher resistance to fracture, and were capable of retaining strength up to a larger extent as compared to low entropy alloy and pure Ni crystal. The higher dislocation density and uniform distribution of dislocation in medium and high entropy alloys leads to plasticity in the crystal after the onset of yielding. Blunting of the crack tip in medium and high entropy alloys was predicted in orientation 1 and 2, whereas crack propagates in orientation 3. This study will help in elucidating the capabilities of medium and high entropy alloys in resisting the opening mode of crack propagation, which can be further utilized to enhance the diversified structural applications of these emerging multi-elemental alloys.
ISSN:0013-7944
1873-7315
DOI:10.1016/j.engfracmech.2021.107536