Mechanical behavior of the HfNbZrTi high entropy alloy after ion irradiation based on micro-pillar compression tests

Peng, Shengyuan; Jin, Ke; Yi, Xiaosu; Dong, Zhaohui; Guo, Xun; Liu, Ying; Cheng, Yangyang; Jia, Nannan; Duan, Huiling; Xue, Jianming

doi:10.1016/j.jallcom.2021.162043

Cited by 10 publications

(1 citation statement)

References 32 publications

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“…Gludovatz et al [4] reported ductile fracture by void growth and coalescence in an fcc FeNiCoCrMn alloy, while Gao et al [17] presented an in-situ TEM investigation on void coalescence for the same alloy. Unlike their fcc counterparts [5], refractory bcc HEAs are, in general, less studied and have received important attention recently [18,19,20,21,22,23,24]. Atomistic simulations have provided valuable insights in the understanding of the exceptional properties of HEAs [25,26,27].…”

Section: Introductionmentioning

confidence: 99%

Atomistic Simulations of Ductile Failure in a b.c.c. High-Entropy Alloy

Aquistapace

Vazquez

Chiarpotti

et al. 2022

High Entropy Alloys & Materials

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Ductile failure is studied in a bcc HfNbTaZr High-Entropy Alloy (HEA) with a pre-existing void. Using molecular dynamics simulations of uniaxial tensile tests, we explore the effect of void radius on the elastic modulus and yield stress. The elastic modulus scales with porosity as in closed-cell foams. The critical stress for dislocation nucleation as a function of the void radius is very well described by a model designed after pure bcc metals, taking into account a larger core radius for the HEA. Twinning takes place as a complementary deformation mechanism, and some detwinning occurs at large strain. No solid-solid phase transitions are identified. The concurrent effects of element size mismatch and plasticity lead to significant lattice disorder. By comparing our HEA results to pure tantalum simulations, we show that the critical stress for dislocation nucleation and the resulting dislocation densities are much lower than for pure Ta, as expected from lower energy barriers due to chemical complexity.

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