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An Analog Macroscopic Technique for Studying Molecular Hydrodynamic Processes in Dense Gases and Liquids
Published on: December 4, 2017
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Dynamics of grain boundary premelting.
M Torabi Rad1, G Boussinot2, M Apel1
1Access e.V., Intzestr. 5, 52072, Aachen, Germany.
Scientific Reports
|December 4, 2020
Summary
Grain boundary (GB) premelting weakens materials. This study reveals that a critical overheating is needed for premelting to occur, influencing material strength and dynamics.
Area of Science:
- Materials Science
- Physics
- Computational Modeling
Background:
- Grain boundary (GB) premelting weakens polycrystalline materials when dry GB free energy exceeds solid-liquid interface energy.
- Previous research on GB premelting was limited to equilibrium conditions.
Purpose of the Study:
- To analyze the dynamics of GB premelting using a multi-phase field model.
- To investigate the evolution of pre-melted polycrystalline microstructures.
Main Methods:
- Simulated steady-state growth of a liquid layer along a dry GB.
- Modeled the evolution of a pre-melted polycrystalline microstructure.
- Utilized a multi-phase field model.
Main Results:
- The disjoining potential critically influences premelting dynamics.
- A critical overheating is required for dry GBs to transform into a pre-melted state.
- Simulations suggest a steady-state velocity for this transformation.
Conclusions:
- Identified a pre-melted polycrystalline equilibrium with unusual grain morphologies and dynamics.
- Determined the regime where dynamics resemble curvature-driven dynamics with enhanced mobility.
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