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Design of exceptionally strong and conductive Cu alloys beyond the conventional speculation via the interfacial energy-controlled dispersion of γ-Al2O3 nanoparticles.

Han SZ, Kim KH, Kang J, Joh H, Kim SM, Ahn JH, Lee J, Lim SH, Han B - Sci Rep (2015)

Bottom Line: In this paper, we demonstrate that these contradictory material properties can be improved simultaneously if the interfacial energies of heterogeneous interfaces are carefully controlled.We uniformly disperse γ-Al2O3 nanoparticles over Cu matrix, and then we controlled atomic level morphology of the interface γ-Al2O3//Cu by adding Ti solutes.Furthermore, the Ti removes impurities (O and Al) in the Cu matrix by forming oxides leading to recovery of the electrical conductivity of pure Cu.

View Article: PubMed Central - PubMed

Affiliation: Structural Materials Division, Korea Institute of Materials Science, Changwon, 51508, Korea.

ABSTRACT
The development of Cu-based alloys with high-mechanical properties (strength, ductility) and electrical conductivity plays a key role over a wide range of industrial applications. Successful design of the materials, however, has been rare due to the improvement of mutually exclusive properties as conventionally speculated. In this paper, we demonstrate that these contradictory material properties can be improved simultaneously if the interfacial energies of heterogeneous interfaces are carefully controlled. We uniformly disperse γ-Al2O3 nanoparticles over Cu matrix, and then we controlled atomic level morphology of the interface γ-Al2O3//Cu by adding Ti solutes. It is shown that the Ti dramatically drives the interfacial phase transformation from very irregular to homogeneous spherical morphologies resulting in substantial enhancement of the mechanical property of Cu matrix. Furthermore, the Ti removes impurities (O and Al) in the Cu matrix by forming oxides leading to recovery of the electrical conductivity of pure Cu. We validate experimental results using TEM and EDX combined with first-principles density functional theory (DFT) calculations, which all consistently poise that our materials are suitable for industrial applications.

No MeSH data available.


Related in: MedlinePlus

Plot in (a) represents electric conductivity and mechanical strength of Cu-0.6%Al-0.4%Ti alloy as function of drawing ratio and successive annealing process, and in (b) comparison of our Cu alloys in electric conductivity and tensile strength with previously reported materials.
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f9: Plot in (a) represents electric conductivity and mechanical strength of Cu-0.6%Al-0.4%Ti alloy as function of drawing ratio and successive annealing process, and in (b) comparison of our Cu alloys in electric conductivity and tensile strength with previously reported materials.

Mentions: To determine whether our materials are appropriate for industrial applications, we processed Alloy 4 into a wire of 0.95 mm in diameter followed by the internal oxidation process at 980 °C for one hour. After removal of the oxide scales on the Cu surface, the diameter decreased to 0.63 mm. We further reduced the cross-sectional area of the wire to 5 % of the initial value with a room-temperature drawing process. Figure 9a reports the measured tensile strength and the electrical conductivity of the drawn wire as a function of drawing ratio (true strain η = ln(A0/A), where A0 and A are the cross-sectional area of the wire before and after drawing, respectively. The electrical conductivity and the tensile strength of the oxidized wire were measured as 93.32 % IACS and 269 MPa, respectively (Fig. 9a). The slight deviation in the electrical conductivity from the IACS value can be attributed to the geometry of the wire specimen. The electrical conductivity measured for a wire sample is more relevant than a plate-type structure because the cross-sectional area and length of the wire can be precisely defined at any stage of the testing procedure.


Design of exceptionally strong and conductive Cu alloys beyond the conventional speculation via the interfacial energy-controlled dispersion of γ-Al2O3 nanoparticles.

Han SZ, Kim KH, Kang J, Joh H, Kim SM, Ahn JH, Lee J, Lim SH, Han B - Sci Rep (2015)

Plot in (a) represents electric conductivity and mechanical strength of Cu-0.6%Al-0.4%Ti alloy as function of drawing ratio and successive annealing process, and in (b) comparison of our Cu alloys in electric conductivity and tensile strength with previously reported materials.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4663622&req=5

f9: Plot in (a) represents electric conductivity and mechanical strength of Cu-0.6%Al-0.4%Ti alloy as function of drawing ratio and successive annealing process, and in (b) comparison of our Cu alloys in electric conductivity and tensile strength with previously reported materials.
Mentions: To determine whether our materials are appropriate for industrial applications, we processed Alloy 4 into a wire of 0.95 mm in diameter followed by the internal oxidation process at 980 °C for one hour. After removal of the oxide scales on the Cu surface, the diameter decreased to 0.63 mm. We further reduced the cross-sectional area of the wire to 5 % of the initial value with a room-temperature drawing process. Figure 9a reports the measured tensile strength and the electrical conductivity of the drawn wire as a function of drawing ratio (true strain η = ln(A0/A), where A0 and A are the cross-sectional area of the wire before and after drawing, respectively. The electrical conductivity and the tensile strength of the oxidized wire were measured as 93.32 % IACS and 269 MPa, respectively (Fig. 9a). The slight deviation in the electrical conductivity from the IACS value can be attributed to the geometry of the wire specimen. The electrical conductivity measured for a wire sample is more relevant than a plate-type structure because the cross-sectional area and length of the wire can be precisely defined at any stage of the testing procedure.

Bottom Line: In this paper, we demonstrate that these contradictory material properties can be improved simultaneously if the interfacial energies of heterogeneous interfaces are carefully controlled.We uniformly disperse γ-Al2O3 nanoparticles over Cu matrix, and then we controlled atomic level morphology of the interface γ-Al2O3//Cu by adding Ti solutes.Furthermore, the Ti removes impurities (O and Al) in the Cu matrix by forming oxides leading to recovery of the electrical conductivity of pure Cu.

View Article: PubMed Central - PubMed

Affiliation: Structural Materials Division, Korea Institute of Materials Science, Changwon, 51508, Korea.

ABSTRACT
The development of Cu-based alloys with high-mechanical properties (strength, ductility) and electrical conductivity plays a key role over a wide range of industrial applications. Successful design of the materials, however, has been rare due to the improvement of mutually exclusive properties as conventionally speculated. In this paper, we demonstrate that these contradictory material properties can be improved simultaneously if the interfacial energies of heterogeneous interfaces are carefully controlled. We uniformly disperse γ-Al2O3 nanoparticles over Cu matrix, and then we controlled atomic level morphology of the interface γ-Al2O3//Cu by adding Ti solutes. It is shown that the Ti dramatically drives the interfacial phase transformation from very irregular to homogeneous spherical morphologies resulting in substantial enhancement of the mechanical property of Cu matrix. Furthermore, the Ti removes impurities (O and Al) in the Cu matrix by forming oxides leading to recovery of the electrical conductivity of pure Cu. We validate experimental results using TEM and EDX combined with first-principles density functional theory (DFT) calculations, which all consistently poise that our materials are suitable for industrial applications.

No MeSH data available.


Related in: MedlinePlus