Significant enhancement in comprehensive mechanical properties of Cr-Fe-Ni-Al-Si-Ti-Cu high-entropy alloy in as-cast state via C microalloying

• Published in: Materials letters Vol. 353; p. 135310
• Main Authors: Zhang, Guangzeng, Hu, Shuai, Wu, Shaojie, Wang, Tan, Cai, Yongfu, Wei, Ran, Guan, Shaokang, Li, Fushan, Chen, Chen
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.12.2023
• Subjects: Coarsening; Heterostructure; High-entropy alloy; Mechanical properties; Microstructure; Heterostructure; Mechanical properties; Microstructure; Coarsening; High-entropy alloy
• ISSN: 0167-577X; 1873-4979
• DOI: 10.1016/j.matlet.2023.135310

•C microalloying was used for structure modification of as-cast heterostructure HEAs.•Minor C leads to coarsening of FCC phase formation and increase FCC/BCC ratio.•C microalloying greatly enhances plasticity and slightly reduces strength. An as-cast CrFeNiAl0.28Si0.08Ti0.02Cu0.01C0.01 high-entropy alloy (HEA) was designed via minor C substitution for Si in a high-strength CrFeNiAl0.28Si0.09Ti0.02Cu0.01 HEA with FCC + BCC dual-phase heterostructure. Compared to its C-free counterpart with fine sideplate structure, this HEA has higher proportion of FCC phase with relatively coarser island-like structure, and exhibits remarkable increase in production of ultimate tensile strength (UTS) and plasticity with ∼ 25 %, while maintaining its UTS to > 1GPa, which has excellent comprehensive mechanical properties in as-cast heterostructure HEAs. High dislocation storage ability is possibly the main reason for high UTS and plasticity of this HEA. This work provides a novel insight for the optimization of microstructure and mechanical properties of heterostructure HEAs in as-cast state.