On the Formation of Eutectics in Variations of the Al10Co25Cr8Fe15Ni36Ti6 Compositionally Complex Alloy

• Published in: Metallurgical and materials transactions. A, Physical metallurgy and materials science Physical metallurgy and materials science, 2021-01, Vol.52 (1), p.143-150
• Main Authors: Manzoni, A. M., Dubois, F., Mousa, M. S., von Schlippenbach, C., Többens, D. M., Yesilcicek, Y., Zaiser, E., Hesse, R., Haas, S., Glatzel, U.
• Format: Article
• Language: English
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; Dendritic structure; Differential scanning calorimetry; Eutectics; Grain boundaries; Hafnium; Homogenization; Materials Science; Metallic Materials; Misalignment; Morphology; Nanotechnology; Structural Materials; Superalloys; Surfaces and Interfaces; Thin Films; Trace elements; Zirconium
• ISSN: 1073-5623; 1543-1940
• DOI: 10.1007/s11661-020-06091-7

Superalloy inspired Al 10 Co 25 Cr 8 Fe 15 Ni 36 Ti 6 compositionally complex alloy is known for its γ - γ ′ microstructure and the third Heusler phase. Variations of this alloy, gained by replacing 0.5 or 1 at. pct Al by the equivalent amount of Mo, W, Zr, Hf or B, can show more phases in addition to this three-phase morphology. When the homogenization temperature is chosen too high, a eutectic phase formation can take place at the grain boundaries, depending on the trace elements: Mo and W do not form eutectics while Hf, Zr and B do. In order to avoid the eutectic formation and the potential implied grain boundary weakening, the homogenization temperature must be chosen carefully by differential scanning calorimetry measurements. A too low homogenization temperature, however, could impede the misorientation alignment of the dendrites in the grain. The influence of grain boundary phases and incomplete dendrite re-orientation are compared and discussed.