Extrusion simulation of TI-6AL-4V for the production of special shaped cross sections
The metallurgical and technological management of the hot extrusion process is related to the microstructural behaviour of the material which depends on its high temperature constitutive relation and on the adopted technological parameters. On the basis of the former determination of the sine hyperbolic constitutive relation and on the performed microstructural analysis, an approach based on the Navier-Stokes' equations has been used for the study of the extrusion of Ti-6Al-4V after a successful application in the hot rolling of micro-alloyed steel and in the extrusion process of austenitic and duplex stainless steels. The result of the simulation has shown the good suitability of this approach for the Ti alloys as well and it has allowed to confirm quantitatively some qualitative considerations stressed about the critical aspects involved in the extrusion of the special cross sections. Particularly, the role of the initial temperature, of the heat developed during the plastic deformation and of its mutual relation with the viscosity of the material, related also to the velocity field imposed to the material by the pulling through the die, have been pointed out.