Statistical approach for understanding the effect of specimen size on the yield stress and its scattering in mechanically-alloyed Cu and ODS-Cu obtained by micro-pillar compression test

Abstract

Oxide Dispersion Strengthening copper (ODS-Cu) alloy has high strength, high thermal conductivity and superior irradiation resistance which are needed for fusion reactor divertor components. In this study, specimen size dependence of the yield stress in Cu and ODS-Cu which were made by mechanical alloying and hot pressing was investigated by micro-pillar compression test. The distributions of yield stress values were different between the sizes, 1, 3 and 5 µm cubic micro-pillars, which can be explained by the inhomogeneous spatial distributions of both the crystallographic grain in matrix and oxide-particles.