Experimental and computational assessment of the temperature dependency of the stacking fault energy in face-centered cubic high-entropy alloys

• Published in: Acta materialia 2024-10, Vol.278, p.120271, Article 120271
• Main Authors: Werner, Konstantin V., Naeem, Muhammad, Niessen, Frank, Zhu, Li, Villa, Matteo, Wang, Xun-Li, Somers, Marcel A.J.
• Format: Article
• Language: English
• Subjects: Deformation mode; Density functional theory; High-entropy alloy; Stacking fault energy; Twinning
• ISSN: 1359-6454
• DOI: 10.1016/j.actamat.2024.120271

The activation of deformation mechanisms in face-centered cubic materials is considered closely related with the stacking fault energy. Experimentally determined stacking fault energy (SFE) values are exclusively positive. However, results obtained by first principle methods predict that the intrinsic SFE of metastable face-centered cubic metals and alloys is negative. It was previously shown that SFE values from the first principle methods and experiments can be reconciled by accounting for the resolved shear stress for Shockley partial dislocations. Determining this resolved shear stress for Shockley partial dislocations is experimentally challenging, making the reconciliation of experimental and first-principles SFE values a laborious exercise. In the present contribution, we demonstrate that the critical resolved shear stress for Shockley partial dislocations and SFE values can be determined from a single in-situ neutron diffraction experiment, thus enabling more confident and efficient reconciliation of experimental and theoretical SFE values. [Display omitted]