TY - JOUR
T1 - Influence of B4C alloying on the phase stability of Fe-Mn-Co-Cr-Si high entropy alloys fabricated using laser powder bed fusion
AU - Moura, I. A.B.
AU - Ribamar, G. G.
AU - Agrawal, P.
AU - Roy, A.
AU - Shen, J.
AU - Rodrigues, P. Freitas
AU - Maawad, E.
AU - Schell, N.
AU - Pereira, A. B.
AU - Oliveira, J. P.
AU - Mishra, R. S.
N1 - Funding Information:
info:eu-repo/grantAgreement/FCT/6817 - DCRRNI ID/LA%2FP%2F0037%2F2020/PT#
info:eu-repo/grantAgreement/FCT/6817 - DCRRNI ID/UIDP%2F50025%2F2020/PT#
info:eu-repo/grantAgreement/FCT/Concurso de avaliação no âmbito do Programa Plurianual de Financiamento de Unidades de I&D (2017%2F2018) - Financiamento Base/UIDB%2F50025%2F2020/PT#
info:eu-repo/grantAgreement/FCT/6817 - DCRRNI ID/LA%2FP%2F0112%2F2020/PT#
The authors acknowledge the infrastructure and support of the Center for Agile & Adaptive and Additive Manufacturing (CAAAM) funded through State of Texas Appropriation #190405-105-805008-220. The authors thank the Materials Research Facility for access to microscopy facilities at the University of North Texas. Nanomodelling and Nanofabrication \u2013 i3N. P.F.R. acknowledges funding by FCT \u2013 Funda\u00E7\u00E3o para a Ci\u00EAncia e a Tecnologia, under projects UID/00285 - Centre for Mechanical Engineering, Materials and Processes, LA/P/0112/2020 and CAPES - Nova\u00E7\u00E3o - 99999.011943/2013-00. The authors acknowledge DESY (Hamburg, Germany), a member of the Helmholtz Association HGF, for providing the experimental facilities. Parts of this research were carried out at the Hereon P07 (HEMS) beamline. The present study was developed in the scope of the Project \u201CAgenda ILLIANCE\u201D [C644919832-00000035 | Project n\u00BA 46], financed by PRR \u2013 Plano de Recupera\u00E7\u00E3o e Resili\u00EAncia under the Next Generation EU from the European Union.
Publisher Copyright:
© 2025 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
PY - 2025/9
Y1 - 2025/9
N2 - This study investigates the impact of 0.25 wt% B4C addition on the microstructure, phase stability, and mechanical properties of metastable Fe40Mn20Co20Cr15Si5 (at.%) high-entropy alloys (HEAs) fabricated via laser powder bed fusion (LPBF). A comparative analysis between B4C-containing (BC) and B4C-free (CS) alloys explored the influence of varying LPBF parameters. Electron backscattered diffraction (EBSD) revealed a strong dependence of microstructure on laser power and scanning speed in CS alloys, with significant variations in grain size and morphology. Conversely, BC alloys exhibited enhanced microstructural stability, indicating a more robust grain growth mechanism due to the influence of B4C. B4C addition also promoted grain refinement and stabilized the γ-f.c.c. phase. Mechanical testing showed a substantial increase in yield strength (YS) from 508 MPa (CS) to 670 MPa (BC) and a moderate increase in ultimate tensile strength (UTS) from 843 MPa (CS) to 854 MPa (BC). However, ductility decreased from 25 % to 5 %. Critically, synchrotron X-ray diffraction revealed deviations from the ideal c/a ratio (1.633) for both alloys. CS alloys showed an increase in c/a ratio after tensile deformation, indicative of a deformation-induced phase transformation, while BC alloys exhibited a decrease, suggesting a distinct deformation mechanism. This novel observation provides key insights into the role of B4C in controlling the deformation behavior of this HEA.
AB - This study investigates the impact of 0.25 wt% B4C addition on the microstructure, phase stability, and mechanical properties of metastable Fe40Mn20Co20Cr15Si5 (at.%) high-entropy alloys (HEAs) fabricated via laser powder bed fusion (LPBF). A comparative analysis between B4C-containing (BC) and B4C-free (CS) alloys explored the influence of varying LPBF parameters. Electron backscattered diffraction (EBSD) revealed a strong dependence of microstructure on laser power and scanning speed in CS alloys, with significant variations in grain size and morphology. Conversely, BC alloys exhibited enhanced microstructural stability, indicating a more robust grain growth mechanism due to the influence of B4C. B4C addition also promoted grain refinement and stabilized the γ-f.c.c. phase. Mechanical testing showed a substantial increase in yield strength (YS) from 508 MPa (CS) to 670 MPa (BC) and a moderate increase in ultimate tensile strength (UTS) from 843 MPa (CS) to 854 MPa (BC). However, ductility decreased from 25 % to 5 %. Critically, synchrotron X-ray diffraction revealed deviations from the ideal c/a ratio (1.633) for both alloys. CS alloys showed an increase in c/a ratio after tensile deformation, indicative of a deformation-induced phase transformation, while BC alloys exhibited a decrease, suggesting a distinct deformation mechanism. This novel observation provides key insights into the role of B4C in controlling the deformation behavior of this HEA.
KW - High entropy alloys
KW - Martensitic phase transformation
KW - Phase stability
KW - X-ray synchrotron radiation
UR - https://www.scopus.com/pages/publications/105007292320
U2 - 10.1016/j.msea.2025.148607
DO - 10.1016/j.msea.2025.148607
M3 - Article
AN - SCOPUS:105007292320
SN - 0921-5093
VL - 941
JO - Materials Science and Engineering: A
JF - Materials Science and Engineering: A
M1 - 148607
ER -