Finite element investigation of part distortion during hot extrusion of titanium alloys

Distortion in cross sectional shape of the extrudate continues to be a problem during the hot extrusion of titanium alloys. Many experimental tryouts are often needed to determine die design and operating conditions for reduced distortion due to the complex relationships among the process variables. To investigate distortion, a finite element model for the glass lubricated hot extrusion process was developed that included all relevant aspects of the hot extrusion process such as induction heating, billet transfer, glass lubrication and metal flow. This model was then used to study the effect of die design and process parameters. Design modifications on the extrusion die was carried out for reduced distortion. The efficacy of this approach was confirmed by demonstrating improvements in industrial trials.