Fabrication of Multiscale-Alumina Particles Reinforced Copper Matrix Composites with High-Energy Ball Milling and Hot Pressing

Abstract

Cu-Al₂O₃ composite materials combining the good electrical of copper matrix and the high hardness of Al₂O₃ ceramic particles show great performance in electronics, electrical sliding contacts fields. However, the relationship of a dilemma between strength and ductility has become a limitation for the development of copper matrix composites. The previous works indicated that fine grain powders can improve interfacial bonding between the copper matrix and Al₂O₃ particles to further enhance strength while maintaining ductility. In the present work, the multiscale-alumina particles reinforced copper matrix composites were successfully fabricated by mixing high-energy ball milling and consolidation of hot-press sintering. SEM and TEM were used to observe the powder morphology and microstructure of Cu-Al₂O₃ composites. The results show that the reinforcing phase Al₂O₃ particles are uniformly dispersed in the copper matrix, which improves interfacial bonding between the copper matrix and Al₂O₃ particles. Especially, the micro Al₂O₃ particles play an important role in achieving an excellent tradeoff of strength and ductility in the Cu-Al₂O₃ composite. In addition, the microhardness of Cu-Al₂O₃ composites can be greatly improved by using the high-energy ball milling and hot-press sintering process. The research idea of this paper can provide a reference for other composite materials that need to improve mechanical properties.

Keywords:

• High energy ball milling
• powder metallurgy
• copper matrix composites
• Al₂O₃ particles

Additional information

Funding

This work was financially supported by the Program for Innovative Research Team (in Science and Technology) in the University of Yunnan Province (No. 14051693), the Basic Research Project of Yunnan Province (No. 202021AS070049 and No. 202102AB080004).