Microstructure and deformation mechanism of (Fe45Mn35Co10Cr10)99C1 high-entropy alloy by laser powder bed fusion
LI Xianglong1, GENG Zhaowen1, CHEN Chao1, LUO Jinru2, ZHOU Kechao1
1. Powder Metallurgy Research Insitute, Central South University, Changsha 410083, China; 2. Department of ?Iron and Steel Metallurgy, University of Science and Technology Beijing, Beijing 100083, China
Abstract：FeMnCoCrC high-entropy alloys were fabricated using laser powder bed fusion (LPBF) from pre-alloyed (Fe45Mn35Co10Cr10)99C1 gas-atomized powder. The effects of LPBF process parameters on the microstructure and mechanical properties of the alloy were investigated by scanning electron microscope, transmission electron microscope, X-ray diffractometer, and room-temperature tensile test, with the aim of elucidating the underlying deformation mechanisms. The results indicate that the FeMnCoCrC high-entropy alloy exhibits a stable single-phase FCC structure, with randomly oriented grains and no significant texture. Furthermore, rich dislocation cell structures formed during the LPBF process, while no carbide precipitation is observed. The alloy fabricated under the optimal parameters (laser power of 120 W and scanning speed of 400 mm/s) demonstrates a enhanced yield strength while maintaining good elongation, achieving a yield strength of 603 MPa, a tensile strength of 850 MPa, and an elongation of 44.0%. The plastic deformation mechanism of the FeMnCoCrC high-entropy alloy is primarily governed by dislocation slip and twinning-induced plasticity, which collectively contribute to a sustained work-hardening capacity. In contrast, the martensite-induced plasticity mechanism is completely suppressed during deformation.
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2025, Vol. 30 
