Aluminum Extrusion Troubleshooting

Pick-up on extrusion surface

Problem Description

Aluminum adheres to die surfaces, transferring defects to the profile.

Cause–Correction Mapping
  • Excess billet temperature
    Cause in: Equipment

      Corrections

    • Reduce billet temperature.

      Disadvantage: Reduced temperature may decrease production.

    • Implement nitrogen shrouding.

  • Improper step behind bearing
    Cause in: Die

      Corrections

    • Provide sufficient relief by mill/grind bearing step (should be 1mm except on critical support areas) or increasing taper.

      Advantage: Better quality finish and reduced scrap.
  • Poor quality billets
    Cause in: Equipment

      Corrections

    • Check billet quality.

Please note that the information provided in this article is intended to be a general guide to the causes and corrections of Pick-up on extrusion surface in aluminum extrusion. However, it is important to note that the specific cause and correction of any particular defect will vary depending on the specific extrusion process, alloy, and other factors. Therefore, it is important to consult with an experienced and professional engineer to ensure that the correct diagnosis is made and the most suitable correction is chosen.