Influence of heat treatments on the formability of the 6061 Al alloy sheets: experiments and GTN damage model


Yıldız R. A., Yılmaz Ş.

INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY, cilt.113, sa.7-8, ss.2277-2299, 2021 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 113 Sayı: 7-8
  • Basım Tarihi: 2021
  • Doi Numarası: 10.1007/s00170-021-06792-2
  • Dergi Adı: INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, IBZ Online, Compendex, INSPEC, DIALNET
  • Sayfa Sayıları: ss.2277-2299
  • Anahtar Kelimeler: 6061 aluminum alloy, Finite element analysis, Forming limit curve, GTN damage model, Sheet metal forming
  • İstanbul Teknik Üniversitesi Adresli: Evet

Özet

The research mainly focused on the forming limit curves (FLC) of the 6061 Al alloy subjected to heat treatments with various (1 mm, 1.6 mm, 2 mm, and 2.5 mm) sheet metal thicknesses. Five peculiar heat treatments, including natural aging temper (T4) and highest-strength (T6) temper, were devised to study the influence of heat treatments on the formability of 6061 Al alloy sheets. Tensile tests were executed to determine the plastic behavior of the alloy under specific heat treatments. Laser marked FLC specimens were deep-drawn with the proposed spring-attached Nakajima deep drawing test setup. A finite element model (FEM) of the deep drawing experiment was constructed to investigate the nucleation and growth mechanism of the voids. The developed model was compared and verified with the experimental FLC, fracture locations, and dome height. The FEM results were differed from the experimental FLC by less than 5% considering all heat treatments and sheet thicknesses. The results declared that sheet metal thickness has a positive effect on the effective strain up to failure. On the other hand, the duration of artificial aging time reduced effective strain to failure controlled by nucleation and growth of voids.