Archives of Metallurgy and Materials (Apr 2024)

Effect of Al–5Ti–1B Addition on Solidification Microstructure and Hot Deformation Behavior of DC-Cast Al–Zn–Mg–Cu Alloy

  • Junho Lee,
  • Namhyuk Seo,
  • Sang-Hwa Lee,
  • Kwangjun Euh,
  • Singon Kang,
  • Seung Bae Son,
  • Seok-Jae Lee,
  • Jae-Gil Jung

DOI
https://doi.org/10.24425/amm.2024.147803
Journal volume & issue
Vol. vol. 69, no. No 1
pp. 145 – 149

Abstract

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This study investigated the effect of adding Al–5Ti–1B grain refiner on the solidification microstructure and hot deformation behavior of direct-chill (DC) cast Al–Zn–Mg–Cu alloys. The grain refiner significantly decreased the grain size and modified the morphology. Fine-grained (FG) alloys with grain refiners exhibit coarse secondary phases with a reduced number density compared to coarse-grained (CG) alloys without grain refiners. Dynamic recrystallization (DRX) was enhanced at higher compression temperatures and lower strain rates in the CG and FG alloys. Both particle stimulated nucleation (PSN) and continuous dynamic recrystallization (CDRX) are enhanced in the FG alloys, resulting in decreased peak stress values (indicating DRX onset) at 450°C. The peak stress of the FG alloys was higher at 300-400°C than that of the CG alloys because of grain refinement hardening over softening by enhanced DRX.

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