[T13] Non Ferrous Materials

[15P-T13-08] Superiorcombination of strength and electrical conductivity in Cu/Al2O3 composite by introducing high-volume-fraction ultrafine grains

*W. Huo¹, J. Zhang², X. Liu³ (1.Northwest Institute for Non-ferrous Metal Research, China, 2.Shaanxi University of Science and Technology, China, 3.Xi’an University of Technology, China)

キーワード：Cu/Al2O3 composite, Ultrafine grains, In-situ Al2O3 nanoparticles, Strengthening mechanisms, Electrical conductivity

High-strength Cu/Al2O3 composites usually exhibit reduced electrical conductivity compared to their low-strength counterparts. This study used a chemical and mechanical alloying-based strategy to fabricate an ultrafine composite powder with low-content reinforcement, forming Cu ultrafine powders covered with in-situ Al2O3 nanoparticles. After consolidation at a relatively lower sintering temperature of 550 ℃, high-volume-fraction ultrafine grains were introduced into the Cu/Al2O3 composite, and many in-situ Al2O3 nanoparticles with an average size of 11.7±7.5 nm were dispersed homogeneously within the Cu grains. As a result, the composite showed an excellent combination of high tensile strength (654±1 MPa) and high electrical conductivity (84.5±0.1% IACS), attributed to the synergistic strengthening effect of ultrafine grains, dislocations and in-situ Al2O3 nanoparticles. This approach using ultrafine composite powder with low-content reinforcement as a precursor followed by low-temperature and high-pressure sintering may have the potential to be applied to large-scale industrial production of high-performance oxide dispersion strengthened alloys.