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Iron-rich medium-entropy alloys (MEAs) have attracted attention due to the balance for cost and properties of alloy. In this study, a combined metastability engineering and eutectic high-entropy alloys (EHEAs) design strategy were employed to develop a cost-effective, iron-rich MEAs for the Fe–Cr–Ni–Al MEAs system using CALPHAD simulations. This approach enabled the tailored control of soft and hard phases within the non-isoatomic MEAs system by manipulating the elemental ratios. Specifically, increasing the aluminum (Al) content promoted the stability of the BCC/B2 phase, and the microstructure of the MEA transitioned from a single-phase FCC structure to a mixed FCC + BCC/B2 structure, culminating in a final single-phase BCC/B2 structure. This BCC/B2 phase precipitation strengthening mechanism led to enhanced microhardness and yield strength in MEAs with high Al content. Notably, the Al 11 -as alloy demonstrated a yield strength of 692.7 ± 30.4 MPa (precipitation strengthening is ∼428.98 MPa, accounting for the true yield strength of the alloy ∼61.9 %), with an ultimate tensile strength reaching a maximum value of 992.3 ± 32.77 MPa. Moreover, the alloy retained a satisfactory elongation of 7.1 ± 2.9 %. These efforts hold promise for the development and application of cost-effective, iron-rich MEAs for the Fe–Cr–Ni–Al MEAs system. • A cost-effective, iron-rich MEAs for the Fe–Cr–Ni–Al MEAs system using CALPHAD simulations. • Thermo-dynamic phase calculation proves to be a valuable tool for MEAs design and phase prediction. • The tailored control of soft and hard phases within the non-isoatomic MEAs system by manipulating the elemental ratios. • Precipitation strengthening plays a significant role in enhancing the overall strength of the Fe 57.88 (CrNi) (42.12- x) Al x MEAs. [ABSTRACT FROM AUTHOR]

Wire arc additive manufacturing (WAAM) has emerged as a promising method for additive manufacturing due to its high efficiency and cost-effectiveness. This study aimed to fabricate Co-based Elgiloy by WAAM based on cold metal transfer technology. An 18-layers thin alloy wall was prepared. The microstructure, texture and mechanical properties of the as-deposited samples were investigated. Results indicated that the prepared alloy had good formability and was composed of a single face center cubic structure. The tensile properties of the alloy exhibited anisotropy due to the large number of columnar grains growing along the building direction in the alloy. The tensile samples along the building direction exhibited lower yield strength but better elongation due to the columnar grain growth direction and the softening effect of the remelted zone. [ABSTRACT FROM AUTHOR]

With low-cost and high-efficiency advantages, wire arc additive manufacturing (WAAM) has become a promising method for preparing high-entropy alloys (HEAs). This study prepared CoCrFeNiMo 0.2 HEA samples using cold metal transfer technology. By changing the deposition parameters, different heat inputs were realized. The forming quality, microstructure, and mechanical properties of the as-deposited CoCrFeNiMo 0.2 HEA samples with different heat inputs were explored by macroscopic observation, optical microscopy, X-ray diffraction, scanning electron microscopy, energy-dispersive spectroscopy, electron backscatter diffraction, microhardness and tensile test at room temperature. Results show that the alloy prepared by WAAM had a typical columnar crystal composition in deposition direction and a strong {100}〈001〉 cubic texture. With the increased heat input, the forming of the sample worsened, and an obvious step effect appeared, increasing the fine grain region between the sample layers. Due to the heat accumulation and poor heat dissipation, the phase with less Mo grew, deteriorating its mechanical properties. The growth direction of columnar crystals in the sample was consistent with the vertical tensile direction, improving the sample's tensile properties perpendicular to the deposition direction. • Wire arc additive manufacturing (WAAM) of CoCrFeNiMo 0.2 high-entropy alloys. • WAAM can produce high-entropy alloys with lower cost and high efficiency. • The effects of heat input on the forming quality of HEAs was investigated. • The microstructure and mechanical properties of the CoCrFeNiMo 0.2 HEAs were investigated. [ABSTRACT FROM AUTHOR]