Plastic deformation induced formation of supersaturated solid solution nanostructure in a dual-phase Cu-Ag alloy

• Published in: Journal of alloys and compounds 2022-05, Vol.903, p.163903, Article 163903
• Main Authors: Han, Z.X., Han, Z., Luo, Z.P., Wang, Z.B.
• Format: Article
• Language: English
• Subjects: Chemical mixing; Copper; Copper base alloys; Dislocations; Dual-phase Cu alloy; Gradient nanostructured; Lamella; Liquid nitrogen; Nanostructure; Plastic deformation; Precipitates; Solid solutions; Supersaturated solid solution; Surface layers; Surface mechanical grinding treatment
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2022.163903

A gradient nanostructured (GNS) surface layer was generated in a dual-phase Cu-Ag alloy by means of surface mechanical grinding treatment at liquid nitrogen temperature. With a decreasing depth in the surface layer, the coarse-grained microstructure of Cu matrix and Ag precipitates gradually converts into a nanolaminated structure of Ag- and Cu-rich phases with simultaneous chemical mixing, and finally forms a homogeneous single-phase supersaturated solid solution (SSS) nanostructure. Accordingly, a dislocation-mediated transportation mechanism was proposed to dominate the chemical mixing of Ag and Cu atoms, i.e., dislocations interacting with solution atoms penetrate the Cu/Ag interface and glide in the neighboring solvent-phase lamella. •A gradient nanostructured (GNS) surface layer was generated in a dual-phase Cu-Ag alloy.•Intermixing of Cu- and Ag-rich phases simultaneously occurs in the GNS surface layer.•A dislocation-mediated transportation mechanism was proposed to dominate the chemical mixing of Ag and Cu atoms.