Enhancing mechanical properties in Ti-Containing FeMn₄₀Co₁₀Cr₁₀C_0.5 High-Entropy alloy through Chi (χ) phase dissolution and precipitation hardening

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Rizi M., Ebrahimian M., Minouei H., Shim S. H., Pouraliakbar H., Fallah V., ...Daha Fazla

MATERIALS LETTERS, cilt.377, 2024 (SCI-Expanded)

• Yayın Türü: Makale / Tam Makale
• Cilt numarası: 377
• Basım Tarihi: 2024
• Doi Numarası: 10.1016/j.matlet.2024.137516
• Dergi Adı: MATERIALS LETTERS
• Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, Chemical Abstracts Core, Chimica, Communication Abstracts, Compendex, INSPEC, Metadex, Civil Engineering Abstracts
• Karadeniz Teknik Üniversitesi Adresli: Hayır

Özet

This research investigates the effects of adding 2 at.% Ti on the microstructure, phase transformation, and mechanical properties of FeMn40Co10Cr10C0.5 high-entropy alloy (HEA) in both as-cast and homogenized conditions. The incorporation of Ti increased the lattice parameter of the FCC matrix and caused greater lattice distortion (similar to 5.9 %) due to the larger atomic radius of Ti. The negative mixing enthalpy of Ti resulted in segregation at interdendritic regions, forming a Ti-rich Chi (chi) phase during solidification. The as-cast structure displayed a dendritic microstructure consisting of 77.9 % FCC, 20.6 % chi, and 1.5 % TiC phases. After homogenization at 1200 degrees C for 2 h, the chi phase was dissolved, increasing the volume fraction of TiC to 24 %. The homogenized sample exhibited a substantial improvement in tensile properties, i.e., with the ultimate tensile strength (UTS) rising from 631 MPa in the as-cast condition to 689 MPa, and yield strength (YS) increasing from 346 MPa to 419 MPa, while maintaining an elongation of similar to 54 %. These enhancements are attributed to solid solution strengthening, increased carbide precipitation, and the dissolution of the chi phase into the FCC matrix.