Experimental and computational analysis of stacking fault energy in B-doped Fe50−XMn30Co10Cr10BX multi-principal elements alloys

• Published in: Journal of alloys and compounds 2023-12, Vol.969, p.172428, Article 172428
• Main Authors: Aguilar-Hurtado, Jose Y., Vargas-Uscategui, Alejandro, Torres-Mejia, Laura Gabriela, Mujica-Roncery, Lais, Zambrano-Mera, Dario, Pantaleone, Stefano, Wang, Bo, Rosenkranz, Andreas, Paredes-Gil, Katherine
• Format: Article
• Language: English
• Subjects: Laser cladding; Multi-component alloys; Stacking fault energy; Strain hardening; Synchrotron X-Ray diffraction
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2023.172428

The effect of boron doping in Fe50−XMn30Co10Cr10BX multi-component alloys on the resulting stacking fault energy has been experimentally and computationally assessed to understand the alloys' deformation mechanisms from structural and thermodynamic perspectives. Firstly, the fcc and hcp phases were identified together with stacking faults along their (110) planes using high-resolution transmission electron microscopy. At the same time, they were theoretically predicted through thermodynamic CALPHAD and ab initio calculations. The average stacking fault energy for the boron-free alloy was 23.9 ± 2.4 mJ/m2, suggesting that the deformation mechanisms relate to dislocation slip and deformation twinning. The average stacking fault energy for the highest boron content (5.4 at%) was 50.1 ± 14.1 mJ/m2, indicating dislocation glide as the possible deformation mechanism. The boron content in the solid solution was modelled. The modelling suggested that the presence of Cr-B, Mn-B and Fe-B bonds points towards forming (Cr,Fe)2B borides, which was experimentally confirmed. The borides, fcc phase stability, and the boron in solid solution contribute to increased stacking fault energy, preventing the motion of Shockley partial dislocations and influencing the ɛ-hcp martensitic transformation. [Display omitted] •The stacking fault energies of Fe50−XMn30Co10Cr10BX were obtained using HR-TEM, CALPHAD and ab initio calculations.•HR-TEM allowed identifying a dual-phase microstructure, stacking faults, and twin formation.•The stacking fault energies of these MPEAs suggest dislocation glide as a possible deformation mechanism.