The beneficial effect of Ce additions to high Fe-containing secondary Al-Si-Mg cast alloys

Moodispaw M. P., Miao J., ÇİNKILIÇ E., Luo A. A.

Journal of Alloys and Compounds, cilt.1009, 2024 (SCI-Expanded) identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 1009
  • Basım Tarihi: 2024
  • Doi Numarası: 10.1016/j.jallcom.2024.176864
  • Dergi Adı: Journal of Alloys and Compounds
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, PASCAL, Aerospace Database, Chemical Abstracts Core, Chimica, Communication Abstracts, Compendex, INSPEC, Metadex, Public Affairs Index, Civil Engineering Abstracts
  • Anahtar Kelimeler: Aluminum alloys, Aluminum recycling, CALPHAD modeling, Casting and solidification, Cerium alloying
  • Hakkari Üniversitesi Adresli: Evet

Özet

The application of high Fe-containing secondary aluminum cast alloys for automotive structural components is restricted due to their low ductility resulting from various intermetallic phases in the solidification microstructure. In this paper, the effect of Ce on secondary Al-Si-Mg-Fe cast alloys was studied systematically using thermodynamic modelling and experimentation. Thermal analysis and microstructure results were compared to thermodynamic simulations. Transmission electron microscopy (TEM) was used to verify the presence of MgAl2Si2, Al2CeSi2, AlCeSi, and AlCeSi2 phases depending on Ce content, in addition to π-Al9FeMg3Si5 and δ-Al3FeSi2. It was found that about 0.25–0.5 % Ce additions improved the tensile elongation by approximately 40 % to above 5 %. AlSiMgFe-0.25Ce alloy showed the highest elongation (5.2 %) and ultimate tensile strength (234 MPa), due to the reduced π-Al9FeMg3Si5 and Mg2Si phases scavenged by Ce additions. Eutectic Si was only weakly modified by Ce additions up to around 1 wt%, and no significant effect on secondary dendrite arm spacing or primary Fe-bearing intermetallic phases was observed. Higher Ce additions lead to excessive Ce-bearing intermetallic formation which is detrimental to the alloy ductility. The beneficial effect of 0.25–0.5 % Ce additions to secondary Al-Si-Mg-Fe cast alloys provides important new understanding to improve these alloys for structural casting applications.