Structural effect of low Al content in the in-situ additive manufactured CrFeCoNiAlx high-entropy alloy

• Published in: Materials letters Vol. 303; p. 130487
• Main Authors: Kuzminova, Yulia, Shibalova, Anastasia, Evlashin, Stanislav, Shishkovsky, Igor, Krakhmalev, Pavel
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15-11-2021; Elsevier BV
• Subjects: Additive manufacturing; Aluminum; Annealing; High entropy alloys; In-situ alloying; Inhomogeneity; Materials Engineering; Materials science; Materialteknik; Microhardness; Microstructure; Phase composition; Powder beds; Precipitates; High-entropy alloys; Annealing; Additive manufacturing; Phase composition; Microstructure; In-situ alloying
• ISSN: 0167-577X; 1873-4979; 1873-4979
• DOI: 10.1016/j.matlet.2021.130487

•In-situ L-PBF CrFeCoNiAlx alloy has the inhomogeneous element distribution.•The CrFeCoNiAlx alloy has a fully fcc structure according to XRD analysis.•Annealing at 1200 °C decreased the microhardness of CrFeCoNiAlx alloy by ~20–35 HV.•The volume of annealing twins is lower for the Al contained alloy.
The current work considers the effect of the low Al fraction (x = 0.01, 0.05, and 0.1) on the microstructure and phase composition of the CrFeCoNiAlx high-entropy alloy in-situ manufactured by powder bed fusion additive technique. The influence of a homogenization annealing at 1200 °C is also presented. The presence of Al powder in the pre-mixed blend decreased the porosity in the as-built samples, while the microhardness did not change significantly. All samples with different Al content demonstrated the chemical inhomogeneity, additionally the Al volatilization was observed. The annealing homogenized the material but led to the Al-rich precipitates. Additionally, the microhardness did not drop significantly for annealed CrFeCoNiAlx samples. The fraction of annealing twins in CrFeCoNiAlx was much lower than in CrFeCoNi after annealing at 1200 °C. According to XRD analyses, only the fcc phase was determined for all conditions.