Laser powder bed fusion to fabricate high-entropy alloy FeCoCrNiMo0.5 with excellent high-temperature strength and ductility

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Structural materials : properties, microstructure and processing, 2024-05, Vol.900, p.146413, Article 146413
• Main Authors: Lin, Danyang, Chen, Qi, Xi, Xin, Ma, Rui, Shi, Zhifeng, Song, Xiaoguo, Xia, Hongbo, Bian, Hong, Tan, Caiwang, Lu, Yongxin, Li, Runsheng
• Format: Article
• Language: English
• Subjects: High-entropy alloy; High-temperature mechanical properties; Laser powder bed fusion; Strengthening mechanism
• ISSN: 0921-5093
• DOI: 10.1016/j.msea.2024.146413

FeCoCrNi, a high-entropy alloy fabricated by laser powder bed fusion, has excellent room-temperature mechanical properties but poor high-temperature mechanical performance. To expand the application of FeCoCrNi, in this study, we added Mo to form σ precipitates, which improved the high-temperature mechanical properties of the alloy via Orowan strengthening. We also elucidated the main deformation mechanism of FeCoCrNiMo0.5, involving the transformation of the deformational mode from dislocation-based motion to twinning deformation. •LPBF-fabricated FeCoCrNiMo0.5 HEA with high strength and ductility at high temperature.•The high-temperature strength and ductility increased significantly after Mo addition.•Superior high-temperature strength–ductility synergy compared to reported alloys.•Change in deformation mechanism and second phase precipitation improved the mechanical properties after Mo addition.