The mechanical energy loss in stressed and -irradiated polycrystalline aluminium

Abstract

The mechanical energy loss in two very pure (99.9999%) deformed aluminium samples (strain, 2%; stress, 12.6 MPa) was studied using the pulse-echo technique at 10 MHz frequency. These two samples were given several -irradiation doses (up to ) at room temperature and liquid-nitrogen temperature. Two relaxation peaks and , dislocation relaxation peaks, were found at temperatures from 179 to 169 K for peak and from 221 to 210 K for peak , having relaxation strengths of - and - , respectively. Both the peak heights and the peak temperatures decrease as the -irradiation dose increases. These variations are explained in terms of the kink-pair formation model.