An upper-bound analysis of the backward extrusion of tubes of complicated internal shapes from round billets

✍ Scribed by W.B. Bae; D.Y. Yang

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 742 KB
• Volume: 36
• Category: Article
• ISSN: 0924-0136
• DOI: 10.1016/0924-0136(93)90028-5

✦ Synopsis

A new kinematically-admissible velocity field is proposed to determine the final-stage extrusion load and the average extruded height in the backward extrusion of internally non-axisymmetric tubes from round billets. The proposed velocity field is applied to the backward extrusion of internally trochoidal gear-shaped tubes and rounded rectangularshaped tubes, the profile function of a rounded rectangle being approximated by using a Fourier series. Experiments are carried out with fully-annealed commercial aluminumalloy billets at room temperature using various shaped punches. The theoretical predictions of the extrusion load are in good agreement with the experimental results and there is generally reasonable agreement in average extruded height between theory and experiment. a,b C,D,E,F,G,p,q H~O~ j* L half lengths of the maj or-and minor-axes of the cross-section optimizing parameters relating to the velocity field initial height of the billet current height of the extruded billet at the ith step upper-bound on the extrusion power upper-bound on the extrusion load

Notation