Cu–Mg dilute alloys- Assessment of strengthening, internal friction, and electrical conductivity

• Published in: Materials chemistry and physics 2024-06, Vol.319, p.129327, Article 129327
• Main Authors: Ozdal, Taner, Nalcaci, Burak, Akyuz, Orhan, Goker, Halil, Kaya, Ali Arslan
• Format: Article
• Language: English
• Subjects: Cu alloys; Elastic modulus; Enthalpy of formation; Miedema approach; Short-range order
• ISSN: 0254-0584; 1879-3312
• DOI: 10.1016/j.matchemphys.2024.129327

Overcoming the strength-conductivity trade-off has long been an issue for commercial copper alloys. However, a synergy between strength and electrical conductivity can be achieved by reasonable adjustment of the microstructure. It is known that the formation of Short-Range Order (SRO) in a solid solution can change the mechanical and electrical behavior of the materials. Currently, the prediction of SRO formation is widely based on computational techniques. In the present study, Miedema's thermodynamical approach is applied for the assessment of alloying elements' potential to form SRO in the copper lattice. According to this methodology, magnesium tends to form SRO with copper. The mechanical, electrical, and structural properties of the oxygen-free copper (Cu-OFC), Cu–Mg0.14 wt%, and Cu–Mg0.50 wt% strips fabricated by continuous extrusion forming process (Conform) have been investigated. According to the optical microscopy investigations, the average grain sizes of the Mg alloyed samples were observed to be lower compared to that of OFC. The Vickers hardness measurements were carried out and the hardness values for Cu-OFC, Cu–Mg0.14, and Cu–Mg0.50 samples were recorded as 56.3 HV, 76.05 HV, and 87.68 HV, and the yield strengths as 80, 150 and 260 MPa, respectively. A decrement in electrical conductivity was observed with the increasing Mg addition. Dynamic elastic modulus test measurements, which refer to internal friction, have been performed by impulse excitation technique to elucidate the presence of SRO in the dilute Cu–Mg systems. The anomalous “bump” formation in the temperature-elastic modulus profiles of the Cu–Mg samples was remarkable which has been attributed to the SRO formation. [Display omitted] •Mechanical, electrical and damping properties of OFC and dilute Cu–Mg were measured.•Mg in Cu–Mg alloys acts as oxygen scavenger during melting thus gives lower oxygen than OFC copper.•Dynamic modulus and damping measurements up to 600 °C showed several peaks.•OFC & Cu–Mg dilute alloys form Short Range Order as indicated by Miedema's thermodynamic approach.