Finite element simulations of thixoforging by using a micro-macro constitutive equation and comparison with experiments

This paper presents different finite element simulations of thixoforging realised on Forge2(c) software. Compression and axial extrusion tests are particularly studied. The constitutive equation used for these simulations is based on a micro-macro approach accounting for the semi-solid microstructural evolution. The constitutive equation parameters are identified thanks to successive comparisons of the simulated load-displacement responses with experimental ones for compression tests on steel semi-solid at different temperatures. The relevance of the modelling is then analysed through extrusion tests. It is shown that the constitutive equation developed by the authors provides simulated results closer to the experimental ones than the classical Norton-Hoff law. It demonstrates the capacity of prediction of such a modelling. Moreover, these simulations give a lot of information concerning the role of parameters such as solid fraction, initial solid skeleton degree of agglomeration, thermal exchanges, or strain rate during thixoforging of high melting point materials