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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

HRTEM images of dispersed γ-Al2O3 nanoparticles in Cu-0.8%Al alloy of planar in (a) and rectangular shapes in (b). Images in (c) represent morphology of Ti soluted γ-Al2O3. The images (d,e) are for TiO2, while (f,g) are for Al3Ti5O2 nanoparticles in Cu-0.4%Al-0.4%Ti alloy after internal oxidation. The (d)~(g) were observed in replica.
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f6: HRTEM images of dispersed γ-Al2O3 nanoparticles in Cu-0.8%Al alloy of planar in (a) and rectangular shapes in (b). Images in (c) represent morphology of Ti soluted γ-Al2O3. The images (d,e) are for TiO2, while (f,g) are for Al3Ti5O2 nanoparticles in Cu-0.4%Al-0.4%Ti alloy after internal oxidation. The (d)~(g) were observed in replica.

Mentions: Figure 6 illustrates the HRTEM analysis of the pure Al2O3 nanoparticles dispersed in Alloy 1 and Alloy 3 with Ti solutes inside (Ti-Al2O3) after two hours of internal oxidation at 980 °C and 1 atm. Alloy 1 includes only gamma-phase alumina (γ–Al2O3, face-centered cubic) with planar and irregular morphologies. This alloy was originated from the interface energies between the Cu matrix and the dispersed γ–Al2O3 nanoparticles. Our HRTEM analysis observed only interfaces, which are most likely the planes of the lowest interfacial energy and force γ–Al2O3 to grow faster in only one direction. The dispersed Ti-Al2O3 nanoparticles in Alloy 3 appeared as polyhedrons (Fig. 6c). HRTEM measurements revealed additional interfaces of and . These findings represent the Ti mitigated interfacial energy differences between the dispersed γ–Al2O3 and the Cu matrix. The dispersed γ–Al2O3 in Alloy 3 grew into spherical structures that were smaller than the oxide nanoparticles in Alloy 1.


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)

HRTEM images of dispersed γ-Al2O3 nanoparticles in Cu-0.8%Al alloy of planar in (a) and rectangular shapes in (b). Images in (c) represent morphology of Ti soluted γ-Al2O3. The images (d,e) are for TiO2, while (f,g) are for Al3Ti5O2 nanoparticles in Cu-0.4%Al-0.4%Ti alloy after internal oxidation. The (d)~(g) were observed in replica.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f6: HRTEM images of dispersed γ-Al2O3 nanoparticles in Cu-0.8%Al alloy of planar in (a) and rectangular shapes in (b). Images in (c) represent morphology of Ti soluted γ-Al2O3. The images (d,e) are for TiO2, while (f,g) are for Al3Ti5O2 nanoparticles in Cu-0.4%Al-0.4%Ti alloy after internal oxidation. The (d)~(g) were observed in replica.
Mentions: Figure 6 illustrates the HRTEM analysis of the pure Al2O3 nanoparticles dispersed in Alloy 1 and Alloy 3 with Ti solutes inside (Ti-Al2O3) after two hours of internal oxidation at 980 °C and 1 atm. Alloy 1 includes only gamma-phase alumina (γ–Al2O3, face-centered cubic) with planar and irregular morphologies. This alloy was originated from the interface energies between the Cu matrix and the dispersed γ–Al2O3 nanoparticles. Our HRTEM analysis observed only interfaces, which are most likely the planes of the lowest interfacial energy and force γ–Al2O3 to grow faster in only one direction. The dispersed Ti-Al2O3 nanoparticles in Alloy 3 appeared as polyhedrons (Fig. 6c). HRTEM measurements revealed additional interfaces of and . These findings represent the Ti mitigated interfacial energy differences between the dispersed γ–Al2O3 and the Cu matrix. The dispersed γ–Al2O3 in Alloy 3 grew into spherical structures that were smaller than the oxide nanoparticles in Alloy 1.

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