Annealing Studies of Bi and Kr Inclusions in Al

This report contains the results of experimental investigations of melting, solidification and growth of Bi and Kr inclusions made by ion implantation into aluminium. The experimental techniques used for this study were x-ray diffraction, transmission electron microscopy, Rutherford backscattering, ion channeling, and grazing-incidence small-angle x-ray scattering The x-ray diffraction signal from crystalline Bi inclusions in Al has been recorded as a function of temperature during heating to temperatures above the bulk melting point and cooling to room temperature.

Data from these measurements have been fitted using models (developed by Pawloiv and Wronski) for the sizedependent melting temperature of small particles, and size distributions for the inclusions have been determined in this way. Transmission electron microscopy has confirmed the melting and solidification of the Bi inclusions in the temperature ranges, in which these processes were observed by x-ray diffraction, establishing the facts that the inclusions melt below the bulk melting point and that a large supercooling is seen.

Information about the amount and depth distribution of the Bi confined in the Al matrix has been derived from Rutherford backscattering measurements. Melting and solidification of Bi inclusions have been observed by means of ion channeling. The results of the investigations of bismuth inclusions in aluminium are compared to previous, similar results for lead inclusions in aluminium.

Finally, preliminary experiments have confirmed that growth of Kr inclusions in Al can be observed using grazing-incidence small-angle scattering.