Microstructures, electrical and mechanical properties of an ODS-Cu alloy containing multi-scale complex oxides

Abstract

Tailoring the size, shape and distribution of nano-particles (NPs) is vital for improving the properties of oxide dispersion strengthened Cu (ODS-Cu). In this study, we used Ti doped Cu–Al powders as starting materials and employed internal oxidation to introduce dense NPs into Cu matrix. Multi-scale oxides are detected in the internally oxidized and hot pressed specimen. It was found that the formation of coarse particles is unavoidable, and they were formed during gas atomization and internal oxidation (along grain boundaries). Ti doping can effectively suppress the growth of the NPs, thus resulting in a particle number density with an order of 1023 m−3. The mechanical and electrical properties of the Ti doped specimen were tested and a comparison is made with Glidcop-25. The yield strength and microhardness of Ti doped ODS-Cu are 54.6 MPa (from 331 MPa to 385.6 MPa) and 33.5 HV0.1 (from 118 HV0.1 to 151.5 HV0.1) higher than that of Glidcop-25, while the conductivity and uniform elongation were reduced by 2.3 % IACS (from 87%IACS to 84.7%IACS) and 1.9 % (from 13.2 % to 11.3 %), respectively. Numerous NPs play a major role in enhancing strength, with modulus hardening (contribution to enhancement reached 66 %) being recognized as the primary mechanism for this enhancement.