Molecular dynamics study on dynamic mechanical behaviour of FeCoCrCuNi high entropy alloy

ABSTRACT

In this paper, molecular dynamics simulation method was used to establish the atomic model of high entropy alloy. The effect of strain rate on the microstructure evolution and dislocation motion of FeNiCoCrCu high entropy alloy was studied by applying tension and compression loads at different strain rates. The results show that the stress–strain curve of FeNiCoCrCu high entropy alloy presents three stages of elastic deformation, yield and plastic deformation under high strain rate. Under tensile load, Frank dislocation causes plastic deformation of the material, and the dislocation reaction between Shockley dislocation and Hirth dislocation generates Stair-rod dislocation. The mechanism of stress relaxation of materials under compression load is the formation of stacking faults. One of the mechanisms of strain hardening of materials is the formation of twins. In addition, stacking faults intersect with each other to produce dislocation reactions, which generate Stair-rod dislocations, maintaining the development of strain hardening effect.

KEYWORDS:

• Molecular dynamics
• high entropy alloy
• high strain rate
• strain hardening

Acknowledgments

We acknowledge the guidance given by Key Laboratory of Science and Technology on Materials on dynamic deformation.

Disclosure statement

No potential conflict of interest was reported by the authors.

Data availability statement

The raw/processed data required to reproduce these findings cannot be shared at this time due to legal and ethical reasons.

Additional information

Funding

This paper is supported by the opening project of State Key Laboratory of Explosion Science and Technology [Beijing Institute of Technology, grant number KFJJ22-06 M]; Funded by Shanxi Basic Research Program [grant number 20210302124196, 202203021211097]; Funded by Foundation Strengthening Plan Technology Field Fund [grant number 2021-JCJQ-JJ-1195].