DYMAT 2009
Volume 2, 2009
DYMAT 2009 - 9th International Conference on the Mechanical and Physical Behaviour of Materials under Dynamic Loading
Page(s) 1075 - 1080
Section Micro-Structural Effects
Published online 15 September 2009
DYMAT 2009 (2009) 1075-1080
DOI: 10.1051/dymat/2009150

Experimental and theoretical investigation of the dynamic properties of aluminum with helium bubbles

B. Glam1, 2, S. Eliezer1, D. Moreno1, Z. Henis1, E. Raicher1, S. Pecker1, M. Sudai1 and D. Eliezer2

1  Soreq Nuclear Research Center, 81800 Yavne, Israel
2  Ben Gurion University of the Negev, Beer Sheva, Israel

Published online: 15 September 2009

The dynamic behavior of aluminum containing helium bubbles was investigated in shock wave experiments. The targets were obtained by mixing melted pure aluminum with 1800 appm 10B powder. After solidification, the targets were neutron irradiated to obtain helium atoms in the bulk from the reaction 10B+n7Li+4He. Helium atoms further accumulated into bubbles by diffusion in the aluminum bulk. Shock wave experiments were performed by accelerating aluminum impactor into three types of samples: (1) pure aluminum, (2) Al-10B and (3) Al-10B with different concentrations of helium bubbles and different radii. The bubbles radii and concentration were determined experimentally using Transmission Electron Microscopy (TEM). The number of helium atoms in a bubble was calculated from the Electron Energy Loss Spectrum (EELS). The following results were obtained in the experiments: The maximum free surface velocity of shocked samples made Al-10B and Al-10B with different concentrations of helium bubbles and different radii was similar, implying that the pressure on the Hugoniot was the same. Moreover, it was found that the spall strength of these samples was the same. However, it was measured that the spall strength of pure aluminum samples was by 47% higher than that of Al-10B and Al-10B with bubbles samples. An equation of state (EOS) model was developed for describing aluminum with helium bubbles. The bubbles radii and concentrations were used as input parameters in the model. The calculated Hugoniot curve for aluminum with bubbles was not sensitive to the existence of helium, for mass ratio of 10−5 between helium and aluminum, typical for the experiments. This finding is in agreement with the experimental results.

© EDP Sciences 2009