Multiscale plastic deformation in additively manufactured FeCoCrNiMo x high-entropy alloys to achieve strength-ductility synergy at elevated temperatures

• Published in: International journal of plasticity 2024, Vol.183
• Main Authors: Lin, Danyang, Hu, Jixu, Wu, Renhao, Liu, Yazhou, Li, Xiaoqing, Sagong, Man Jae, Tan, Caiwang, Song, Xiaoguo, Kim, Hyoung Seop
• Format: Article
• Language: English
• Subjects: Deformation twinning; Elevated temperature; Molecular dynamics simulation; Multiscale plastic deformation
• ISSN: 1879-2154; 0749-6419
• DOI: 10.1016/j.ijplas.2024.104142

The application of structural metals in extreme environments necessitates materials with superior mechanical properties. Mo-doped FeCoCrNi high-entropy alloys (HEAs) have emerged as potential candidates for use in such demanding environments. This study investigates the hightemperature performance of FeCoCrNiMox HEAs with varying Mo contents (x = 0, 0.1, 0.3, and 0.5) prepared by laser powder bed fusion additive manufacturing. The mechanical properties were evaluated at room and 600 degrees C temperatures, and the microstructures were characterized using scanning electron microscopy, electron backscatter diffraction, energy dispersive X-ray spectroscopy, and transmission electron microscopy. The intrinsic dislocation cell patterning, solid-solution strengthening, nanoprecipitation, and twinning effects collectively modulated the plastic deformation behavior of the samples. The high-temperature mechanical performance was comprehensively analyzed in conjunction with ab initio calculations and molecular dynamics simulations to reveal the origin of the experimentally observed strength-ductility synergy of FeCoCrNiMo0.3. This study has significant implications for FeCoCrNiMox HEAs and extends our understanding of the structural origins of the exceptional mechanical properties of additively manufactured HEAs.