Thermal conductivity of high-dose neutron irradiated beryllium and titanium beryllide

Abstract

The neutron irradiation of Be, Be-5Ti and Be-7Ti samples in the HFR, Petten, the Netherlands, at temperatures of 710, 800, 940, 1040 K up to damage doses of 23, 31, 36, 38 dpa, respectively, leads to a degradation in the thermal conductivity, depending on the Be-phase content and the radiation-induced porosity in these materials. The Be samples irradiated at the two highest irradiation temperatures of 940 and 1040 K have a maximum drop in the thermal conductivity because these samples have the highest porosity. A lesser decrease in the thermal conductivity of Be-5Ti and Be-7Ti materials occurs for all four irradiation temperatures of 710, 800, 940, 1040 K. The thermal conductivity of Be-5Ti and Be-7Ti depends on the Be-phase content in both initial and irradiated states. The Be-7Ti material contains a minimum volume fraction of the Be-phase, therefore, it has minimum values of the thermal conductivity for both unirradiated (43–50 W/(m·K)) and irradiated (30–38 W/(m·K)) states.