Cu-Al interfacial compounds and formation mechanism of copper cladding aluminum composites
(1. School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China;
2. School of Mechanical and Electrical Engineering, Hebei University of Engineering, Handan 056038, China)
Abstract: Copper cladding aluminum (CCA) rods with the section dimensions of 12 mm in diameter and 2 mm in sheath thickness were fabricated by vertical core-filling continuous casting (VCFC) technology. The kinds and morphology of interfacial intermetallic compounds (IMCs) were investigated by SEM, XRD and TEM. The results showed that the interfacial structure of Cu/Al was mainly composed of layered γ1(Cu9Al4), cellular θ(CuAl2), and α(Al)+θ(CuAl2) phases. Moreover, residual acicular ε2(Cu3Al2+x) phase was observed at the Cu/Al interface. By comparing the driving force of formation for ε2(Cu3Al2+x) and γ1(Cu9Al4) phases, the conclusion was drawn that the ε2(Cu3Al2+x) formed firstly at the Cu/Al interface. In addition, the interfacial formation mechanism of copper cladding aluminum composites was revealed completely.
Key words: copper cladding aluminum composite; vertical core-filling continuous casting; interfacial formation mechanism