Bridge design influences on the pressure conditions in the welding chamber for porthole die extrusion

Research output: Contributions to collected editions/worksArticle in conference proceedingsResearchpeer-review

Authors

  • Francesco Gagliardi
  • Martin Schwane
  • Teresa Citrea
  • Matthias Haase
  • Noomane Ben Khalifa
  • A. Erman Tekkaya

Porthole die extrusion of lightweight alloys is used for the production of profiles, which may have complex cross section geometries. The mechanical properties of these profiles are deeply affected by the seam welds, which are generated in hollow profiles along the whole length. The seam welds result from the rejoining of the material streams in the welding chamber of the porthole die. The joining phase and hence the seam weld quality are strongly influenced by the temperature and the pressure conditions in the welding chamber. Those process conditions can be adjusted by a proper die design. In this work, the focus lies on the feeder section of the extrusion die, which consists of a set of bridges, whose shapes influence the material entry in the welding chamber. A numerical study was carried out to investigate different bridge shapes with regard to the pressure inside the welding chamber and the punch load. Subsequently, the volume of the bridge was fixed to isolate and better investigate the influence of the shape. It was observed that bridge designs leading to higher flow distortion cause higher pressure decrement along the welding plane and, consequently, degradation of the welding conditions.

Original languageEnglish
Title of host publicationMetal Forming 2014
EditorsFabrizio Micari, Livan Fratini
Number of pages8
Volume622-623
PublisherTrans Tech Publications
Publication date2014
Pages87-94
ISBN (print)978-3-03835-193-1
ISBN (electronic)978-3-03826-576-4, 978-3-03795-889-6
DOIs
Publication statusPublished - 2014
Externally publishedYes
Event15th International Conference on Metal Forming 2014 - Palermo, Italy
Duration: 21.09.201424.09.2014
Conference number: 15

    Research areas

  • Contact pressure, Extrusion, FEM, Porthole
  • Engineering