Reactivity of plasma-sintered beryllium in dry air and moisture at high temperature

Beryllium (Be) metal is a candidate material of not only neutron-multiplier for fusion reactors but also a water-cooled target material for an accelerator-based boron neutron capture therapy. To investigate its reactivity in dry air and 1% H2O/Ar at 873-1273 K, Be samples were fabricated by a novel plasma-sintering method proposed herein. Because of its reactivity in dry atmosphere, parabolic oxidation of Be along grain boundaries was predominant up to 1173 K at an activation energy of 52 kJ/mol, while catastrophic oxidation occurred at 1273 K. The introduction of H2O facilitated breakaway in Be oxidation. Hence, the weight and H2 concentration of Be tested in 1% H2O/Ar dramatically increased from 973 K, while samples tested for 24 h were completely oxidized in appearance.