Atomic scale investigation of Cr precipitation in copper

Abdelahad Chbihi (1) , Xavier Sauvage (1) , Didier Blavette (1)

1 GPM - Groupe de physique des matériaux

The early stage of the chromium precipitation in copper was analyzed at the atomic scale by Atom Probe Tomography (APT). Quantitative data about the precipitate size, 3D shape, density, composition and volume fraction were obtained in a Cu-1Cr-0.1Zr (wt.%) commercial alloy aged at 713K. Surprisingly, nanoscaled precipitates exhibit various shapes (spherical, plates and ellipsoid) and contain a large amount of Cu (up to 50%), in contradiction with the equilibrium Cu-Cr phase diagram. APT data also show that some impurities (Fe) may segregate along Cu/Cr interfaces. The concomitant evolution of the precipitate shape and composition as a function of the aging time is discussed. A special emphasis is given on the competition between interfacial and elastic energy and on the role of Fe segregation.

Mots clés: Cu alloy; chromium; precipitation; coarsening; phase transformation

Domaines: Science des matériaux [cond-mat.mtrl-sci]

Abdelahad Chbihi, Xavier Sauvage, Didier Blavette. Atomic scale investigation of Cr precipitation in copper. Acta Materialia, 2012, 60 (11), pp.4575-4585. ⟨10.1016/j.actamat.2012.01.038⟩. ⟨hal-00718119⟩