Influence of Ag addition on the microstructure and properties of copper-alumina composites prepared by internal oxidation
Journal article, 2017

In present study, Cu-Al2O3 composites with both higher micro-hardness and electrical conductivity were fabricated by internal-oxidizing Cu-Al and Cu-Al-Ag sheets at 950 degrees C for 2 h. A small amount of Ag was doped as additives with atomic ratio of Ag/Al ranging from 0 to 0.25. Effects of Ag addition on microstructures, electrical conductivity and micro-hardness were investigated. Results show that the morphology and size distribution of Al2O3 in internal-oxidized Cu-Al alloys were highly sensitive to Ag addition. The size of Al2O3 precipitates decreased from similar to 63 nm to similar to 37 nm when increasing Ag content. Moreover, a large number of triangular Al2O3 precipitate with similar size was observed by field emission scanning electron microscope (FESEM) and high-resolution transmission electron microscopy (HRTEM) in Ag-doped Cu-Al2O3 composites. The orientation relationship between triangular Al2O3 and Cu matrix was [112](Cu)//[110](Al2O3), (11 (1) over bar)(Cu)//(002)(Al2O3) and (2 (2) over bar 0)(Cu)//(2 (2) over bar 0)(Al2O3). Increasing the amount of Ag enhances the electrical conductivity and mechanical strength simultaneously. The optimal electrical and mechanical properties which were 85.9% IACS and 162 HV respectively, were obtained when atomic ratio of Ag/Al was similar to 1: 4 in internal-oxidized Cu- Al2O3-Ag alloy.

Electrical conductivity


Internal oxidation

Copper-based composites



Xiyi Zhou

Chalmers, Materials and Manufacturing Technology, Surface and Microstructure Engineering

D. Q. Yi

Central South University

Lars Nyborg

Chalmers, Materials and Manufacturing Technology

Z. Hu

Central South University

J. Huang

Central South University

Yu Cao

Chalmers, Materials and Manufacturing Technology, Surface and Microstructure Engineering

Journal of Alloys and Compounds

0925-8388 (ISSN)

Vol. 722 962-969

Subject Categories

Materials Chemistry



More information