DISPLACEMENT AND DEFORMATION DURING TUBE BILLET EXTRUSION
The aim of this work is to determine displacement and deformation during hot tube billet extrusion with various die shapes. Calculations were performed for extrusion of titanium VT6 alloy at 1000 °C. Computational experiments involved the use of the finite element method realized in the QFORM software complex. The solution of the boundary value problem shows the effect of the configuration of the deformation zone during extrusion on the distribution of stresses and strains. The average stress, strain rates and strains are analyzed. The analysis of these parameters allows to identify the causes of heterogeneity of mechanical properties in extruding semi-finished products, as well as possible defect formation. Conclusion is made about the absence of dead zones at the die angle of 45°. A region of increased strain rates exists near the die surface in which metal fracture is hardly probable. The greatest compressive stresses are localized along the container wall and along the work surface of the pressure pad. Average stresses decrease towards the exit of the deformation zone, therefore, these regions of metal may be subjected to fracture due to micro- or macrocrack formation. The scope of the results is technological support of the work of forging workshops, as well as research organizations.