Microstructure of a new ODS Cu–0.7wt-%Cr–0.11wt-%Zr material produced by a novel powder metallurgical method

Abstract

A new oxide dispersion strengthened Cu–0.7wt-%Cr–0.11wt-%Zr material was processed via mechanical alloying (MA) and hot isostatic pressing (HIP). A fine dispersion of yttria particles (Y2O3) was incorporated to the Cu matrix via the addition of yttrium (III) acetate tetrahydrate (C6H9O6Y·4H2O) powder (Y3ATH), which decomposed during thermomechanical processing and subsequent thermal annealing. The microstructure after consolidation by HIP revealed the coexistence of zones with a low and high density of precipitates/particles, LDPZ and HDPZ, respectively. The HDPZ were characterized by fine grains with an average size of ∼300 nm and fine Y–O rich particles (∼40 nm) and Cr rich coarse particles (∼215 nm), homogenously distributed in the Cu matrix. However, the LDPZ contained coarse grains containing 60°/〈111〉 (Σ3) twins’ boundaries.