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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

Averaged sizes and volume densities in (a) and in (b) aspect ratios of dispersed oxide nanoparticles in Cu matrix after 2 hours of oxidation at 980 °C under ambient atmosphere. Relationships of conductivity-hardness and strength-ductility for the oxide nanoparticles after oxidations for 2 or 4 hours were shown at (c,d), respectively.
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f5: Averaged sizes and volume densities in (a) and in (b) aspect ratios of dispersed oxide nanoparticles in Cu matrix after 2 hours of oxidation at 980 °C under ambient atmosphere. Relationships of conductivity-hardness and strength-ductility for the oxide nanoparticles after oxidations for 2 or 4 hours were shown at (c,d), respectively.

Mentions: To characterize the detailed compositions of the oxides, we used energy-dispersive X-ray (EDX) spectroscopic analysis for Alloy 4 in Table 1 (Cu-0.6Al-0.4Ti). The results (Fig. 4) indicated that Ti partially substitutes Al in Al2O3 nanoparticles (i.e., a solid solution). Figure 5 illustrates the average particle size, aspect ratio and volume density of the oxide particle over the Cu alloys as a function of the atomic fraction of Ti/Al. This figure provides clear correlations between these parameters. The particle size and the aspect ratio decrease as the atomic fraction increases. The volume density is proportional to the atomic fraction. Alloy 4 contains more Ti and Al (in terms of total weight) than Alloy 3, and both the size and the aspect ratio are larger, but the volume density is almost identical. Therefore, atomic fractions of Ti to Al describe the system better than weight.


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)

Averaged sizes and volume densities in (a) and in (b) aspect ratios of dispersed oxide nanoparticles in Cu matrix after 2 hours of oxidation at 980 °C under ambient atmosphere. Relationships of conductivity-hardness and strength-ductility for the oxide nanoparticles after oxidations for 2 or 4 hours were shown at (c,d), respectively.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f5: Averaged sizes and volume densities in (a) and in (b) aspect ratios of dispersed oxide nanoparticles in Cu matrix after 2 hours of oxidation at 980 °C under ambient atmosphere. Relationships of conductivity-hardness and strength-ductility for the oxide nanoparticles after oxidations for 2 or 4 hours were shown at (c,d), respectively.
Mentions: To characterize the detailed compositions of the oxides, we used energy-dispersive X-ray (EDX) spectroscopic analysis for Alloy 4 in Table 1 (Cu-0.6Al-0.4Ti). The results (Fig. 4) indicated that Ti partially substitutes Al in Al2O3 nanoparticles (i.e., a solid solution). Figure 5 illustrates the average particle size, aspect ratio and volume density of the oxide particle over the Cu alloys as a function of the atomic fraction of Ti/Al. This figure provides clear correlations between these parameters. The particle size and the aspect ratio decrease as the atomic fraction increases. The volume density is proportional to the atomic fraction. Alloy 4 contains more Ti and Al (in terms of total weight) than Alloy 3, and both the size and the aspect ratio are larger, but the volume density is almost identical. Therefore, atomic fractions of Ti to Al describe the system better than weight.

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