A finite element model of the squeeze casting process

Abstract

Purpose-To present a numerical model of squeeze casting process. Design/methodology/approach-The modelling consists of two parts, namely, the mould filling and the subsequent thermal stress analysis during and after solidification. Mould filling is described by the Navier-Stokes equations discretized using the Galerkin finite element method. The free surface is followed using a front tracking procedure. A thermal stress analysis is carried out, assuming that a coupling exists between the thermal problem and the mechanical one. The mechanical problem is described as an elasto-visco-plastic formulation in an updated Lagrangian frame. A microstructural solidification model is also incorporated for the mould filling and thermal stress analysis. The thermal problem is solved using enthalpy method. Findings-During the mould-filling process a quasi-static arbitrary Lagrangian-Eulerian (ALE) approach and a microstructural solidification model were found to be applicable. For the case of the thermal stress analysis the influence of gap closure, effect of initial stresses (geometric nonlinearity), large voids and good performance of a microstructural model have been demonstrated. Research limitations/implications-The model can also be applied to the simulation of indirect castings. The final goal of the model is the ability to simulate the forming of the material after mould filling and during the solidification of the material. This is possible to achieve by applying arbitrary contact surfaces due to the sliding movement of the cast versus the punch and die. Practical implications-The presented model can be used in engineering practice, as it incorporates selected second-order effects which may influence the performance of the cast. Originality/value-During the mould-filling procedure a quasi-static ALE approach has been applied to SQC processes and found to be generally applicable. A microstructural solidification model was applied which has been used for the thermal stress analysis only. During the thermal stress analysis the influence of gap closure and initial stresses (geometric nonlinearity) has been demonstrated.

Numerical Modeling and Experimental Validation of Free Surface Flow Problems

“…In this context of fixed discretizations, pioneering methods are Marker-and-Cell (MAC) [99,153] , Volume Of Fluid (VOF) [104,185] , pseudo-concentration [98,130,177,218], and Level Set (LS) [144,189,198]. Such techniques are extensively used to describe moving interfaces as well as many other related formulations [5,9,36,41,43,47,49,57,60,62,70,71,74,86,88,90,102,115,119,129,131,138,146,147,159,212,214,216,220].…”

Modelling in Squeeze Casting Process-Present State and Future Perspectives

“…Finite elemental analysis method (FEM) [31][32][33][34][35], finite volume method (FVM) [36], finite difference methods (FDM) [37], and enthalpy method are the mathematical tools which were employed to simulate squeeze casting processes. On observing from the literatures, all the models which are capable of making effective simulations were noted.…”

Numerical modeling of hot tearing formation in metal casting and its validations

“…Numerical modeling can also answer some of the critical questions concerning mold filling, microstructure formation, casting properties, mechanisms of casting defect formation, and the final shape of casting (see e.g. 2–5 and references therein). It has been used to reduce the time required in new product design cycles and as a tool for quality assurance.…”