Abstract
To describe the thermomechanical behaviour of the semi-solid state during alloy solidification, specific viscoplastic constitutive laws are derived for the coherent and non-coherent regime of the mush. For the coherent semi-solid regime an original viscoplastic flow potential is derived, which includes micro-structural parameters. This potential takes also isotropic hardening, pressure dependence of yielding and the strength difference in tension and compression into account. For the non-coherent mushy state of suspensions under shear loading, a simplified viscoplastic potential is adopted by neglecting pressure effects on the solid dendrites. Continuity at mechanical coherency is imposed and allows the reduction of the model parameters of the non-coherent regime. The developed constitutive laws are implemented in Abaqus via a user-defined CREEP routine. Simulations of uniaxial tension, compression or pure shear experiments allow identifying the model parameters of an A356 aluminium alloy.
Export citation and abstract BibTeX RIS
Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.