1. A combined experimental and first-principles based assessment of finite-temperature thermodynamic properties of intermetallic Al3Sc
- Author
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Esin, Vladimir A., Gupta, Ankit, Tas, Bengü, Korbmacher, Dominique, Dutta, Biswanath, Neitzel, Yulia, Grabowski, Blazej, Hickel, Tilmann, Esin, Vladimir, Divinski, Sergiy, Wilde, Gerhard, Neugebauer, Jörg, Centre des Matériaux (MAT), MINES ParisTech - École nationale supérieure des mines de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
heat capacity ,Materials science ,Intermetallic ,Thermodynamics ,02 engineering and technology ,precipitation ,01 natural sciences ,Heat capacity ,lcsh:Technology ,Article ,Thermal expansion ,Matrix (mathematics) ,[SPI]Engineering Sciences [physics] ,Phase (matter) ,0103 physical sciences ,Coupling (piping) ,General Materials Science ,lcsh:Microscopy ,lcsh:QC120-168.85 ,010302 applied physics ,lcsh:QH201-278.5 ,ab initio ,lcsh:T ,Anharmonicity ,021001 nanoscience & nanotechnology ,Microstructure ,lcsh:TA1-2040 ,Al-Sc alloys ,lcsh:Descriptive and experimental mechanics ,lcsh:Electrical engineering. Electronics. Nuclear engineering ,0210 nano-technology ,coefficient of thermal expansion ,lcsh:Engineering (General). Civil engineering (General) ,lcsh:TK1-9971 - Abstract
We present a first-principles assessment of the finite-temperature thermodynamic properties of the intermetallic Al3Sc phase including the complete spectrum of excitations and compare the theoretical findings with our dilatometric and calorimetric measurements. While significant electronic contributions to the heat capacity and thermal expansion are observed near the melting temperature, anharmonic contributions, and electron–phonon coupling effects are found to be relatively small. On the one hand, these accurate methods are used to demonstrate shortcomings of empirical predictions of phase stabilities such as the Neumann–Kopp rule. On the other hand, their combination with elasticity theory was found to provide an upper limit for the size of Al3Sc nanoprecipitates needed to maintain coherency with the host matrix. The chemo-mechanical coupling being responsible for the coherency loss of strengthening precipitates is revealed by a combination of state-of-the-art simulations and dedicated experiments. These findings can be exploited to fine-tune the microstructure of Al-Sc-based alloys to approach optimum mechanical properties.
- Published
- 2021
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