Experimental Determination of the Allotropic Transition Temperature Between Tetragonal and Orthorhombic Al[subscript 4]Sm Metastable Phases
Abstract not provided
Napolitano, R. E.↗
Engineering topics
Napolitano, R. E.
Publications and source records attributed to Napolitano, R. E..
Observation of η-Al41Sm5 reveals motif-aware structural evolution in Al-Sm alloys
Explore the source record for details and available documents.
36 MATERIALS SCIENCE↗
A computational study of diffusion in a glass-forming metallic liquid
In this study, liquid phase diffusion plays a critical role in phase transformations (e.g. glass transformation and devitrification) observed in marginal glass forming systems such as Al-Sm. Controlling transformation pathways in such cases requires a comprehensive description of diffusivity, including the associated composition and temperature dependencies. In our computational study, we examine atomic diffusion in Al-Sm liquids using ab initio molecular dynamics (AIMD) and determine the diffusivities of Al and Sm for selected alloy compositions. Non-Arrhenius diffusion behavior is observed in the undercooled liquids with an enhanced local structural ordering. Through assessment of our AIMD result, we construct a general formulation for Al-Sm liquid, involving a diffusion mobility database that includes composition and temperature dependence. A Volmer-Fulcher-Tammann (VFT) equation is adopted for describing the non-Arrhenius behavior observed in the undercooled liquid. Furthermore, the composition dependence of diffusivity is found quite strong, even for the Al-rich region contrary to the sole previous report on this binary system. The model is used in combination with the available thermodynamic database to predict specific diffusivities and compares well with reported experimental data for 0.6 at.% and 5.6 at.% Sm in Al-Sm alloys.
36 MATERIALS SCIENCE↗