Finite element analysis with deformation behavior modeling of globular microstructure in forming process of semi-solid materials

• Published in: International journal of mechanical sciences 1999-12, Vol.41 (12), p.1423-1445
• Main Authors: Kang, C.G., Jung, H.K.
• Format: Article
• Language: English
• Subjects: Alloys; Applied sciences; Compressible visco-plastic; Computer simulation; Exact sciences and technology; Finite element method; Forming; Fundamental areas of phenomenology (including applications); Globular microstructure; Inelasticity (thermoplasticity, viscoplasticity...); Mathematical models; Metallographic microstructure; Metals. Metallurgy; Morphology; Other forming methods; Physics; Production techniques; Semi-solid material (SSM); Separation coefficient; Solid fraction; Solid mechanics; Solidification; Strain; Stress analysis; Structural and continuum mechanics; Viscoelasticity, plasticity, viscoplasticity; Viscoplasticity
• ISSN: 0020-7403; 1879-2162
• DOI: 10.1016/S0020-7403(98)00107-6

The behavior of alloys in a semi-solid state depends on the imposed stress state and on the morphology of the phase which can vary from dendritic to globular microstructure. An estimation of characteristic behavior in a compression simulation with semi-solid materials (SSMs) is made using the finite element method (FEM) and a proposed, new stress–strain relationship formulation with a separation coefficient. The proposed theoretical models for the compression forming process involve simultaneous calculations performed with solid-phase deformation and the liquid-phase flow saturating the interstitial space. A simulation process considering solidification phenomena is implemented with non-isothermal conditions in two-dimensions. To analyze the compression process of SSMs, a new stress–strain relationship is described, and the compression analysis is performed by using a compressible visco-plastic model for the solid phase and Darcy’s law of fluid flow through a porous medium for the liquid phase. The validity of the proposed models is investigated by comparing the calculated results with experimental data for the relationship between engineering stress and true strain, and the distributions of solid fraction, temperature effective strain, etc., are calculated.