Improvement of interfacial bonding and mechanical properties of Cu-Al2O3 composite by Cr-nanoparticle-induced interfacial modification

Abstract

The strength and ductility of copper matrix composites are usually limited due to the interfacial debonding between the reinforcement and matrix. Interfacial debonding is mainly caused by the interfacial stress induced by the differences in elastic modulus and thermal expansion coefficient (CTE) between the reinforcement and matrix. Cu-Cr-Al2O3 composite with Cr nanoparticles precipitated at the interface of Cu and Al2O3 was fabricated. It was found that the hardness of Cu-1 wt% Cr-4 wt% Al2O3 composite is higher than that of Cu-5 wt% Al2O3 composite over the temperature range from 25 °C to 1000 °C. Notably, the hardness increment reached 133% at 1000 °C. In addition, the compressibility increased 36% for Cu-1 wt% Cr-4 wt% Al2O3 composite compared with Cu-5 wt% Al2O3. The finite element simulation results confirmed that the interfacial residual stress in Cu-Al2O3 composite decreased by adding Cr, resulting in the improvement in mechanical properties.