Bubbles formation in helium ion irradiated Cu/W multilayer nanocomposites: Effects on structure and mechanical properties

JOURNAL OF NUCLEAR MATERIALS

卷:473

Article

Callisti, M.¹  Karlik, M.²  Polcar, T.^1,3 

[1] Univ Southampton, Fac Engn & Environm, Natl Ctr Adv Tribol Southampton, Southampton SO17 1BJ, Hants, England

[2] Czech Tech Univ, Fac Nucl Sci & Phys Engn, Dept Mat, Trojanova 13, Prague 12000 2, Czech Republic

[3] Czech Tech Univ, Fac Elect Engn, Dept Control Engn, Tech 2, Prague 16627 6, Czech Republic

关键词: Multilayers;    Heterostructures;    Interfaces;    Irradiation;    Helium bubbles;    Nanoindentation;    Transmission electron microscopy (TEM);   

DOI  :  10.1016/j.jnucmat.2016.02.006

来源: Elsevier

【 摘 要 】

This study investigates the effects of He bubbles on structural and mechanical properties of sputter-deposited Cu/W multilayers. A multilayer with a periodicity of 10 nm was deposited and subjected to helium ion irradiation with two different fluences. He bubbles formed mostly in Cu layers and their distribution was affected by He concentration and radiation damage. According to SRIM calculations, in low He concentration regions bubbles formed mostly along interfaces, while more homogeneously distributed bubbles were found in Cu layers and along columnar grain boundaries in higher He concentration regions. We suggest that the capability of interfaces to annihilate point defects is weakened by the He bubbles shielding effect. Nanoindentation tests revealed a hardness decrease amounting to similar to 0.5 and similar to 1 GPa for low and high fluences, respectively. The observed softening effect is attributed to He storage-induced changes in residual stresses and columnar grain boundary/interfacial sliding facilitated by He bubbles. (C) 2016 Elsevier B.V. All rights reserved.

【 授权许可】

Free