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.