Microstructure and properties of a Co-free Fe50Mn27Ni10Cr13 high entropy alloy

• Published in: Journal of alloys and compounds 2021-01, Vol.851, p.1, Article 156842
• Main Authors: Nutor, Raymond Kwesi, Azeemullah, Muhammad, Cao, Q.P., Wang, X.D., Zhang, D.X., Jiang, J.Z.
• Format: Article
• Language: English
• Subjects: Corrosion; Corrosion resistance; Corrosion resistant alloys; Deformation mechanisms; Elongation; High entropy alloys; Immersion tests (corrosion); in-situ SEM/EBSD; in-situ tensile test; Microstructure; Properties (attributes); Stacking faults; Sulfuric acid; Tensile deformation; Tensile strength; Tensile tests; Thermomechanical treatment; TWIP steels
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2020.156842

The microstructure, mechanical and corrosion properties of a cost-effective face-center cubic (fcc)-structured Co-free Fe50Mn27Ni10Cr13 high entropy alloy (HEA), which is developed here, has been studied using a comprehensive approach of ex-situ tensile tests, in-situ SEM/EBSD tensile measurements, ex-situ TEM studies, Tafel polarization, and immersion tests. After thermo-mechanical treatments, this alloy exhibits a tensile strength of 463 MPa and elongation of over 40% which are comparable to other expensive HEAs. A miniature-designed dog-bone specimen for in-situ SEM/EBSD measurements was successfully employed to study the underlying deformation mechanisms of the alloy, exhibiting the double-fiber 111 and 001 texture typical of TWIP steels. Nano-, meso- and macro-scale studies revealed that the excellent combination of strength and ductility of this newly-developed cost-effective fcc-structured HEA is originated from the formation of stacking faults and nano-twins during tensile deformation. This newly-developed alloy also exhibits good corrosion resistance in the following solutions: NaCl > NaOH >H2SO4 > HCl. The corrosion resistance was mostly found to be dependent on the amount of Mn-oxide in the passive film formed on the surface of the alloy. This work, following the non-equiatomic HEA design strategy, develops a cost-effective HEA with a good combination of mechanical with corrosion properties, which will trigger more investigations. •Novel Fe50Mn27Ni10Cr13 HEA exhibits a 111 and 001 double-fiber texture after deformation.•Successful in-situ EBSD/SEM tensile-test at higher strains.•Dislocation glide and mechanical twinning deformation mechanisms.•Good corrosion response as follows: NaCl > NaOH > H2SO4 > HCl.