1. Semi-solid deformation of Al-Cu alloys: a quantitative comparison between real-time imaging and coupled LBM-DEM simulations
- Author
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Su, T.C., O'Sullivan, C., Nagira, T., Yasuda, H., Gourlay, C.M., and Engineering & Physical Science Research Council (EPSRC)
- Subjects
Technology ,Science & Technology ,Synchrotron radiation ,Materials Science ,Dilatancy ,0204 Condensed Matter Physics ,Materials Science, Multidisciplinary ,MECHANICAL-BEHAVIOR ,RHEOLOGICAL BEHAVIOR ,DISTINCT ELEMENT METHOD ,Image analysis ,Discrete element method ,HOT TEARING FORMATION ,SHEAR BEHAVIOR ,LATTICE-BOLTZMANN METHOD ,ALUMINUM-COPPER ALLOYS ,Metallurgy & Metallurgical Engineering ,Semi-solid ,IN-SITU OBSERVATION ,MG-AL ,PARTICLE ,0912 Materials Engineering ,Materials ,0913 Mechanical Engineering - Abstract
Semi-solid alloys are deformed in a wide range of casting processes; an improved understanding and modelling capability is required to minimise defect formation and optimise productivity. Here we combine thin-sample in-situ X-ray radiography of semisolid Al-Cu alloy deformation at 40–70% solid with 2D coupled lattice Boltzmann method - discrete element method (LBM-DEM) simulations. The simulations quantitatively capture the key features of the in-situ experiments, including (i) the local contraction and dilation of the grain assembly during shear deformation; (ii) the heterogeneous strain fields and localisation features; (iii) increases in local liquid pressure in regions where liquid was expelled from the free surface in the experiment; and (iv) decreases in liquid pressure in regions where surface menisci are sucked-in in experiments. The verified DEM simulations provide new insights into the role of initial solid fraction on the stress-deformation response and support the hypothesis that the behaviour of semi-solid alloys can be described using critical state soil mechanics.
- Published
- 2018