Core Concepts
The composition and crystal structure strongly influence the mechanical properties and activated slip systems in the hexagonal C14 Laves and rhombohedral μ-phases of the Ta-Fe(-Al) system.
Abstract
This study systematically investigates the mechanical properties and deformation mechanisms of the hexagonal C14 Laves and rhombohedral μ-phases in the binary Ta-Fe and ternary Ta-Fe-Al systems.
Key highlights:
- Nanoindentation tests reveal that the indentation modulus of the Laves phase decreases with increasing Ta content, while the hardness remains relatively constant. In the μ-phase, both the indentation modulus and hardness show a decreasing trend with increasing Ta content.
- The addition of Al to the ternary system does not significantly change the mechanical properties of the Laves and μ-phases compared to the binary system.
- Slip trace analysis and TEM investigations show that the Laves phase primarily deforms via non-basal slip, while the basal plane is the favored slip plane in the μ-phase.
- Partial substitution of Fe with Al in the ternary phases slightly increases the proportion of non-basal slip compared to the binary phases.
- DFT calculations provide insights into the effect of composition and magnetic ordering on the elastic properties of the Laves and μ-phases.
The results contribute to a better understanding of the deformation behavior of these brittle topologically close-packed (TCP) phases, which is crucial for controlling their plasticity in high-performance structural and functional materials.
Stats
"The indentation modulus of the binary Laves phase samples ranges from 282 GPa to 307 GPa, decreasing with increasing Ta content."
"The indentation modulus of the binary μ-phase samples decreases from 269 GPa to 250 GPa with increasing Ta content."
"The hardness of the binary Laves phase samples remains relatively constant around 17.4-17.6 GPa."
"The hardness of the binary μ-phase samples first decreases from 16.0 GPa to 15.4 GPa and then increases again to 16.8 GPa with increasing Ta content."
Quotes
"The composition strongly influences the indentation modulus in the binary Ta-Fe system, showing a decreasing trend with increasing Ta content."
"The addition of Al, however, does not lead to a significant change of the mechanical properties of the ternary TCP phases."
"The investigation of the deformation mechanisms revealed that the Laves phase primarily deforms via non-basal slip while the basal plane is the favoured slip plane in the μ-phase."