Mechanical properties of irradiated nanowires - A molecular dynamics study

JOURNAL OF NUCLEAR MATERIALS

卷:467

Article

Figueroa, Emilio^1,2  Tramontina, Diego^3,4  Gutierrez, Gonzalo¹  Bringa, Eduardo³ 

[1] Univ Chile, Fac Ciencias, Dept Fis, Grp NanoMat, Santiago 653, Chile

[2] Univ Tecnol Metropolitana, Dept Fis, Fac Ciencias Nat Matemat & Medio Ambiente, Santiago 7800002, Chile

[3] Univ Nacl Cuyo, Fac Ciencias Exactas & Nat, RA-5500 Mendoza, Argentina

[4] Univ Mendoza, Inst Bioingn, RA-5500 Mendoza, Argentina

关键词: Radiation damage;    Nanowires;    Mechanical properties;    Computer simulation;   

DOI  :  10.1016/j.jnucmat.2015.10.036

来源: Elsevier

【 摘 要 】

In this work we study, by means of molecular dynamics simulation, the change in the mechanical properties of a gold nanowire with pre-existing radiation damage. The gold nanowire is used as a simple model for a nanofoam, made of connected nanowires. Radiation damage by keV ions leads to the formation of a stacking fault tetrahedron (SFT), and this defect leads to a reduced plastic threshold, as expected, when the nanowire is subjected to tension. We quantify dislocation and twin density during the deformation, and find that the early activation of the SFT as a dislocation source leads to reduced dislocation densities compared to the case without radiation damage. In addition, we observed a total destruction of the SFT, as opposed to a recent simulation study where it was postulated that SFTs might act as self-generating dislocation sources. The flow stress at large deformation is also found to be slightly larger for the irradiated case, in agreement with recent experiments. (C) 2015 Elsevier B.V. All rights reserved.

【 授权许可】

Free