Abstract
Hardness test, electrical resistivity measurement, and electron microscope observation were carried out on arc-melted beryllium specimens with up to 0.2 wt% iron which were heat-treated at 900°C and aged at 400° to 700°C for various times.
From the results it was deduced that the amount of small dislocation loops produced probably by precipitation of excess quenched-in vacancies increased with increasing iron content, and that the vacancies combined preferentially with iron atoms, which resulted in the slowing down of their migration rate. The amount of the loops increased by the subsequent ageing, accompanied with the precipitation of iron onto the loops as well as onto other defects such as grain boundaries and dislocation lines.
