First-principles calculations of stability, electronic and elastic properties of the precipitates present in 7055 aluminum alloy
| Autor: | Cheng Huang, Hong-bang Shao, Yuanchun Huang, Zhengbing Xiao, Yunlong Ma |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
010302 applied physics
Bulk modulus Materials science Ionic bonding Modulus Thermodynamics Statistical and Nonlinear Physics 02 engineering and technology 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Shear modulus Structural stability 0103 physical sciences Density functional theory 0210 nano-technology Anisotropy Metallic bonding |
| Zdroj: | International Journal of Modern Physics B. 32:1850104 |
| ISSN: | 1793-6578 0217-9792 |
| DOI: | 10.1142/s0217979218501047 |
| Popis: | The structural stability, electronic structures and elastic properties of the strengthening precipitates, namely Al3Zr, MgZn2, Al2CuMg and Al2Cu, present in 7055 aluminum alloy were investigated by the first-principles calculations based on density functional theory (DFT). The optimized structural parameters are in good agreement with literature values available. It is found that Al3Zr has the strongest alloying ability and structural stability, while for MgZn2, its structural stability is the worst. The calculated electronic results indicate that covalent bonding is the dominant cohesion of Al3Zr, whereas the fractional ionic interactions coexisting with metallic bonding are found in MgZn2, Al2CuMg and Al2Cu. The elastic constants C[Formula: see text] of these precipitates were calculated, and the bulk modulus, shear modulus, Young’s modulus, Poisson’s ratio and universal elastic anisotropy were derived. It is suggested that MgZn2is ductile, whereas Al3Zr, Al2CuMg and Al2Cu are brittle, and the elastic anisotropies of them increase in the following sequence: Al3Zr[Formula: see text]MgZn2[Formula: see text]Al2CuMg[Formula: see text]Al2Cu. The formation of MgZn2and Al3Zr should be promoted by increasing the compositions of Zn and Zr to improve the alloy’s performance further. |
| Databáze: | OpenAIRE |
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