Strength-ductility synergy in FeMnCoCrC high entropy alloys through Nb addition and tailoring carbide morphology

SABOKTAKIN RIZI M., Ebrahimian M., Minouei H., Shim S. H., VAROL T., GÜLER O., ...Daha Fazla

Journal of Alloys and Compounds, cilt.1044, 2025 (SCI-Expanded) identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 1044
  • Basım Tarihi: 2025
  • Doi Numarası: 10.1016/j.jallcom.2025.184424
  • 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: Aging heat treatment, Carbide morphology, High-entropy alloys, Mechanical properties, Precipitation strengthening
  • Karadeniz Teknik Üniversitesi Adresli: Evet

Özet

This study systematically explores the influence of adding 2 at% niobium (Nb) and thermal aging treatments on the microstructure and mechanical properties of FeMn40Co10Cr10C0.5 high-entropy alloys (HEAs). Two alloys were fabricated, one Nb-free and one Nb-containing, both subjected to cold rolling and subsequent aging at 900 °C, for 20 h. The Nb-free alloy demonstrated a stable, single-phase FCC structure containing uniformly dispersed nanoscale spherical Cr-rich carbides (∼100–200 nm), which significantly enhanced mechanical strength without compromising ductility. Conversely, the Nb-containing alloy developed a dual-phase microstructure, characterized by eutectic Nb2C carbides evolving into directionally aligned, coarsened lamellae upon aging. This morphological transformation, combined with the complete dissolution of the ε-phase, markedly enhanced yield strength (568 MPa) and ultimate tensile strength (870 MPa), while preserving excellent ductility (∼51 %). These findings underline the critical role of Nb addition and controlled thermal processing in tailoring carbide morphology and phase stability, providing an effective strategy to achieve exceptional strength–ductility synergy in carbon-containing FCC-type HEAs.