This study investigated the thermodynamic parameters, microstructures and electrochemical properties of TiMoVWCr and TiMoVNbZr bio-refractory high-entropy alloys (bio-RHEAs) prepared using the vacuum arc remelting process. The alloys were characterized using field emission scanning electron microscopy, field emission electron probe microanalyzer, X-ray diffraction analysis, and potentiodynamic polarization tests. The determined thermodynamic values of Ω-parameter, atomic size difference and valence electron concentration for the TiMoVWCr and TiMoVNbZr bio-RHEAs were within the range of solid solution formation. A high-temperature stable single BCC1 phase was obtained using the thermodynamic equilibrium calculations for the TiMoVWCr and TiMoVNbZr systems. The TiMoVWCr alloy microstructure comprised a dendrite, an inter-dendrite, and a second phase, while TiMoVNbZr alloy comprised a dendrite and an inter-dendrite. The TiMoVWCr alloy forming the stable single body-centered cubic solid solution demonstrated homogeneous microstructure and high phase stability. Moreover, pitting resistances of TiMoVWCr and TiMoVNbZr bio-RHEAs were remarkably superior to that of ASTM F75 alloy.

本研究调查了使用真空电弧重熔工艺制备的 TiMoVWCr 和 TiMoVNbZr 生物难熔高熵合金 (bio-RHEAs) 的热力学参数、微观结构和电化学性能。使用场发射扫描电子显微镜、场发射电子探针显微分析仪、X 射线衍射分析和动电位极化测试对合金进行了表征。TiMoVWCr 和TiMoVNbZr bio-RHEAs 的Ω 参数、原子尺寸差异和价电子浓度的确定热力学值在固溶体形成范围内。使用 TiMoVWCr 和 TiMoVNbZr 系统的热力学平衡计算获得了高温稳定的单 BCC1 相。TiMoVWCr 合金显微组织包括枝晶、枝晶间和第二相，而 TiMoVNbZr 合金包含一个枝晶和一个枝晶间。形成稳定的单体心立方固溶体的 TiMoVWCr 合金表现出均匀的微观结构和高的相稳定性。此外，TiMoVWCr 和 TiMoVNbZr bio-RHEAs 的耐点蚀性能明显优于 ASTM F75 合金。