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Evolution of the As‐Cast Grain Microstructure of an Ultrasonically Treated Al–2Cu Alloy
Author(s) -
Wang Gui,
Croaker Paul,
Dargusch Matthew,
McGuckin Damian,
StJohn David
Publication year - 2018
Publication title -
advanced engineering materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.938
H-Index - 114
eISSN - 1527-2648
pISSN - 1438-1656
DOI - 10.1002/adem.201800521
Subject(s) - materials science , equiaxed crystals , nucleation , microstructure , alloy , metallurgy , acoustic streaming , convection , casting , ultrasonic sensor , grain size , heat transfer , grain growth , coupling (piping) , temperature gradient , composite material , mechanics , thermodynamics , physics , quantum mechanics , acoustics
The evolution of the grain structure of an Al–2Cu alloy is investigated numerically during its solidification while being subjected to ultrasonic treatment. A CAFE (Cellular Automation Finite Element) model coupling fluid flow, heat transfer, nucleation, and grain growth is developed and validated by comparing the results of both numerical simulations and physical experiments. The model successfully describes hydrodynamic fields generated by ultrasonic treatment and their influence on microstructural evolution. This validated model is then used to study the influence of the duration of ultrasonic treatment on temperature distribution and grain structure. A predominantly equiaxed grain structure developed due to the low temperature gradient throughout the melt is a result of the enhanced convection. These results highlight the critical role played by the convection induced by acoustic streaming during casting, that is, facilitating nucleation and grain growth.