In order to design and develop new marine structural materials with a balance of strength-toughness-corrosion resistance, in this work, the synergistic effects of Al and Ti on the microstructure, mechanical and corrosion resistance properties of CoCrFeNi(Al_0.3Ti_0.2)_x high-entropy alloys were systematically investigated. With the addition of Al and Ti, the L1₂-γ' phase formed in the alloys significantly improves the mechanical properties, but excessive addition will lead to the formation of Al-Ti-rich B2 phase structure, which reduces the ductility of the alloy. For the corrosion resistance of the alloys in 3.5 wt. % NaCl solution, the increase of Al and Ti contents improves the stability of the passive film, while effectively reduces the corrosion current density and passivation current density of the alloys. However, the precipitation with a large number of strengthening phases aggravates the segregation of elements, resulting in a decrease in the pitting corrosion resistance and the resistance to the pit propagation of the alloy. In addition, compared with conventional structural alloys, the L1₂-strengthened dual-phase CoCrFeNiAl_0.15Ti_0.1 high-entropy alloy possesses an excellent balance of strength-toughness-corrosion resistance. This work also provides guidance for the future development of high-performance high-entropy alloy systems for marine engineering.

为了设计和开发具有强度-韧性-耐腐蚀性能平衡的新型海洋结构材料，在这项工作中，Al和Ti的协同作用对CoCrFeNi(Al _0.3 Ti _0.2 ) _x的显微组织、力学和耐腐蚀性能性能的影响系统地研究了高熵合金。添加 Al 和 Ti 后，L1 ₂合金中形成的-γ'相显着提高了力学性能，但过量添加会导致形成富Al-Ti B2相结构，降低合金的延展性。对于 3.5 wt 合金的耐腐蚀性。%NaCl溶液中，Al和Ti含量的增加提高了钝化膜的稳定性，同时有效地降低了合金的腐蚀电流密度和钝化电流密度。但大量强化相的析出加剧了元素的偏析，导致合金的耐点蚀性和耐点蚀扩展能力下降。此外，与常规结构合金相比，L1 ₂强化双相CoCrFeNiAl _0.15 Ti_0.1高熵合金具有优异的强度-韧性-耐腐蚀性平衡。该工作还为海洋工程高性能高熵合金系统的未来发展提供了指导。