Development of Y_2O_3 dispersion strengthened Cu alloy using Cu_6Y and Cu_2O addition through the MA-HIP process

摘要

A copper-based material is the recent main trend of advanced heat sink materials for the solid divertor systems, providing an optimal combination of excellent mechanical strength and superior thermal conductivity under severe neutron irradiation environment. In particular, oxide dispersion strengthened Cu (ODS-Cu) alloy with yttrium oxide (Y2O3) nano-particles is one of the promising materials because of the lower influence of the particles on thermal conductivity and the higher resistance to coarsening of the particles due to their thermodynamic stability. The metal Y as the Y2O3 source has been used to fabricate ODS-Cu alloys in the previous work. In this study, we used the Cu6Y intermetallic compound as the new Y source material to form Y2O3 particles during mechanical alloying (MA) followed by hot isostatic pressing (HIP) process, and successfully fabricated ODS-Cu alloy with Y2O3 nano-particles using the Cu6Y compound. The effects of Cu2O addition in this process as the oxidant material were also investigated. Y2O3 nano-particles with typical size of 30 nm were successfully formed into the Cu intra-grains and around grain boundaries, and the density of the Y2O3 nano-particles increased by the Cu2O addition. Cu2O addition promoted the oxidation of Y from the Cu6Y compound, forming Y2O3 nano-particles.