EUROPEAN CONGRESS AND EXHIBITION ON ADVANCED MATERIALS AND PROCESSES - EUROMAT 2021

FCC compositionally complex High Entropy Alloys (HEA) have been reported to exhibit good mechanical properties, radiation-resistance properties and excellent phase stability. Crystal defects structure are obviously at the origin of many observed properties [1]. It is expected that the complex local atomic environment of High Entropy Alloys (which also gives rise to the high configurational entropy) in irradiated alloys, promotes the recombination of Frenkel pairs whereas in conventional stainless steels, defects are mobile and thus tend to aggregate into clusters [1][2]. This phenomenon would be at the origin of better resistance of HEA to radiation damages. For a better understanding of the impact of crystal defect structure (especially dislocations) on High Entropy Alloys, atomistic simulations techniques are employed. In this framework we developed an interatomic potential using an embedded atom method for the quaternary Fe-Ni-Cr-Mn system to model movement of dislocations and their interaction with radiation defects such as vacancies and interstitials (clusters) [2][3]. The properties of the developed interatomic potential have been validated and compared with available experimental and theoretical data. This was done by calculating the vacancy formation energy, lattice parameter, elastic properties and stacking fault energy of different chemical composition of Fe-Ni-Cr-Mn system.

keywords:Atomistic simulation, Crystal defects, Interatomic potential, Stacking fault energy.

Reference
[1] N.A.P. Kiran Kumar, C. Li, K.J. Leonard, H. Bei, S.J. Zinkle.
Microstructural stability and mechanical behavior of FeNiMnCr high entropy alloy under ion irradiation Acta Materialia 2016; 113:230-244.

[2] G.Bonny, N.Castin, D.Terentyev Interatomic potential for studying ageing under irradiation in stainless steels: the FeNiCr model alloy Modelling Simul.Mater.Sci 2013; 14:1-14.

[3] J.B. Baudouin Modeling and simulation with molecular dynamics of the edge dislocation behavior in the presence of Frank loops in austenitic stainless steels Fe-Ni-Cr PhD thesis 2014;135:19-30,42–68.