Effect of bearing length assignment on velocity distribution in extrusion of an unsymmetrical solid profile

• Main Authors: Ammu, V. N. S. U. Viswanath, Padole, Pramod M., Agnihotri, Anupam, Dumpala, Ravikumar
• Format: Conference Proceeding
• Language: English
• Subjects: Casting; Cross-sections; Extrusion dies; Flow control; Flow velocity; Friction drag; Iterative methods; Pressure distribution; Simulation; Technical papers; Thickness; Velocity distribution; Velocity gradient
• ISSN: 0094-243X; 1551-7616
• DOI: 10.1063/5.0183015

In aluminium extrusion, die design is a critical step to achieve metal flow control and produce uniform profile output at the die exit. Designers often rely on the bearing length variation method to locally control metal flow. In this technical paper, numerical simulation studies were carried out to assign bearing lengths across the cross-section of an asymmetric profile. The profile has cross-sectional variations with thicknesses of 10, 5, and 4mm spread across a width of 70 mm where relative bearing lengths assignment is complex. From the studies, it was found that constant bearing length has produced velocity gradient with metal flow velocities in the range of 19.65 to 81.2 mm/s across the cross-section indicating profile distortion at die exit. Based on simulation results, it was observed that the combined effect of radial distance centre from die centre and thickness variations greatly influences the local metal flow velocities. Accordingly, bearing lengths were varied in an iterative manner to alter the local friction drag. Bearing lengths were assigned depending on the ratio of local velocity to mean flow velocity. Optimization of bearing lengths was achieved in the die, and simulation results indicated uniform profile output in velocity. Also, the temperature and pressure distribution were studied.