Characterisation and comparison of process Chains for producing automotive structural parts from 7xxx Aluminium Sheets

Philipp A. Schuster, Johannes A. Österreicher, Georg Kirov, Christof Sommitsch, Olaf Kessler, Ermal Mukeli

Research output: Contribution to journalArticleResearchpeer-review

Abstract

Due to their high specific strength, EN AW-7xxx aluminium alloys are promising materials for reducing the weight of automotive structural parts. However, their formability at room temperature is poor due to pronounced natural ageing. Therefore, we investigated hot stamping and W-temper forming for EN AW-7075 and a modified variant of EN AW-7021. For hot stamping of the modified EN AW-7021, a low-temperature stabilisation heat treatment (pre-aging at 80 °C for 1 h) was incorporated into the process chain design to inhibit natural ageing after forming. The process chains were compared with respect to dimensional accuracy, mechanical properties, microstructure, precipitation status (assessed by differential scanning calorimetry) and crashworthiness. It was found that hot stamping is suitable to form failure-free parts with good dimensional accuracy for both alloys while W-temper forming suffers from springback. Within a time-span of 21 days after forming, hardness values of hot stamped and stabilised parts did not increase significantly. Compared to non-stabilised parts, stabilised parts also showed significantly improved folding behaviour in quasi-static compression testing and absorbed approximately 15% more energy.

Original languageEnglish
Article number305
JournalMetals
Volume9
Issue number3
DOIs
Publication statusPublished - 1 Mar 2019

Fingerprint

Aluminum sheet
Stamping
Aging of materials
Compression testing
Crashworthiness
Formability
Differential scanning calorimetry
Aluminum alloys
Stabilization
Hardness
Heat treatment
Mechanical properties
Temperature
Microstructure

Keywords

  • 7021
  • 7075
  • Aluminium
  • Crashworthiness
  • Hot stamping
  • Stabilisation heat treatment
  • W-temper forming

ASJC Scopus subject areas

  • Materials Science(all)

Cite this

Characterisation and comparison of process Chains for producing automotive structural parts from 7xxx Aluminium Sheets. / Schuster, Philipp A.; Österreicher, Johannes A.; Kirov, Georg; Sommitsch, Christof; Kessler, Olaf; Mukeli, Ermal.

In: Metals, Vol. 9, No. 3, 305, 01.03.2019.

Research output: Contribution to journalArticleResearchpeer-review

Schuster, Philipp A. ; Österreicher, Johannes A. ; Kirov, Georg ; Sommitsch, Christof ; Kessler, Olaf ; Mukeli, Ermal. / Characterisation and comparison of process Chains for producing automotive structural parts from 7xxx Aluminium Sheets. In: Metals. 2019 ; Vol. 9, No. 3.
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