Effects of cobalt content on the microstructures of Fe-9Al-30Mn-1C-xCo alloys

Chin Sung Chen, Che Tong Lin, Pei Wen Peng, Mao Suan Huang, Keng Liang Ou, Ling Hung Lin, Chih Hua Yu

Research output: Contribution to journalArticlepeer-review

14 Citations (Scopus)


The microstructure of the as-cast Fe-Al-Mn-C-Co alloy was a mixture of the (α + DO3 + γ + κ) phases. However, the microstructure of the alloy with 9.0 wt.% Co content was nearly a single γ phase. As the alloys underwent heat treatment between 1000 °C and 1100 °C, their microstructure changed to the (γ + κ) phase. The κ phase carbides ((Fe,Mn)3AlCx) had an ordered L′12-type structure with lattice parameter a = 0.385 nm and were formed by a spinodal decomposition during quenching. The alloy with Co content ≥5.0 wt.% was aged at 650-950 °C, a (γ + κ) → (γ + κ + Co23C6) → (γ + Co23C6) phase transition was observed in the matrix and on the grain boundaries. It is believed that the addition of Co not only stabilizes the austenitic structure at high temperatures but also inhibits and/or prolongs the precipitation of the κ phase during the aging process.

Original languageEnglish
Pages (from-to)346-351
Number of pages6
JournalJournal of Alloys and Compounds
Issue number1-2
Publication statusPublished - Mar 18 2010


  • Cobalt carbide
  • Fe-Al-Mn-C-Co alloy
  • Microstructure
  • Transmission electron microscopy
  • κ phase

ASJC Scopus subject areas

  • Mechanics of Materials
  • Mechanical Engineering
  • Metals and Alloys
  • Materials Chemistry


Dive into the research topics of 'Effects of cobalt content on the microstructures of Fe-9Al-30Mn-1C-xCo alloys'. Together they form a unique fingerprint.

Cite this