Eur. Phys. J. B (2012) 85: 345
https://doi.org/10.1140/epjb/e2012-30044-0

Regular Article

A first-principles study on the helium doped grain boundary in metal Al

¹ Laboratory of Computational Physics, Institute of Applied Physics Mathematics and Computational, P.O.Box 8009-26, Beijing 100083, P.R. China
² Center for Applied Physics and Technology, Peking University, Beijing 100871, P.R. China

^a e-mail: Junchen@iapcm.ac.cn

Received: 16 January 2012
Received in final form: 14 July 2012
Published online: 18 October 2012

Abstract

The He doped Al Σ3 grain boundary (GB) is investigated by using a first principles method. The segregation energy and elastic coefficient of He doped Al Σ3 GB are calculated. The theoretical tensile tests on the He + Σ3 GB are implemented and the calculated stress-strain curve shows that He doping will reduce the strength of the material and induces a double stress maxima effect in the fracture process. The bondlength and charge distribution analysis indicate that the reducing strength of the He-doped GB model can be attributed to the weak interaction of the Al-He bond and the weakening of the Al-Al bond nearby the He atom.