Effect of plasma sintering on densification and oxygen content of beryllium powder

Beryllium has attracted a great attention as multiplier in fusion reactors and moderator and reflector in fission reactors. The use of plasma-sintering method has been suggested as a way to fabricate beryllium specimens which have similar properties with those produced by conventional methods (e.g., hot pressing and hot isostatic pressing). In general, the plasma-sintering process (PSP but also known as spark plasma sintering, SPS, or pulsed electric current sintering - PECS) consists of applying uniaxial pressure and pulsed current. It is considered that the pulsed current activates particle surfaces and eliminates impurities prior to a common thermomechanical treatment. However, only scarce information on its effect from the viewpoints of its contribution to densification by uniaxial pressing and oxygen content is available and verification of its effect is still needed for pure beryllium. Since the plasma activation could be a useful process to eliminate the impurities by recycling of radioactive materials, its effect should be also taken into consideration. In this study, the influence of parameters of the pulsed current on compaction of beryllium powder and oxygen content of fabricated samples was investigated. The perspectives for the further use of PSP operation from the point of view of its influence on fabrication parameters and reprocessing of the beryllium-based radioactive waste are discussed in the final part of this paper.