Effect of temperature on the growth of inert gas bubbles in metals

This paper reports on the effect of temperature on the growth of inert gas bubbles in irradiated copper-boron and aluminium-boron alloys. The growth of helium gas bubbles in copper-boron alloys has been studied in the temperature range of 1173-1318 K. It is shown that beyond 1303 K the rate of bubble growth decreases. Similar characteristics of the bubble growth have been observed in aluminium-boron alloys between 860 and 913 K. Thus an unexpected retardation in the bubble growth is observed near the melting point in both of these systems. Swelling studies in irradiated copper-boron alloys also corroborate these results. This is the first reported observation of this type and has important implications on the use of metallic fuels in nuclear reactors. Current theories of inert gas bubbles cannot explain these results. (orig.)