[论文解读] An experimental high-throughput to high-fidelity study towards discovering Al-Cr containing corrosion-resistant compositionally complex alloys

Debashish Sur, Emily F. Holcombe+10 more|arXiv (Cornell University)|Feb 15, 2023

Advanced Materials Characterization Techniques参考文献 76被引用 5

一句话总结

本研究提出了一种高通量至高保真度的实验方法，用于识别具有优异耐腐蚀性的含Al-Cr成分复杂合金（CCAs）。通过结合快速合成、电化学阻抗谱（EIS）以及扩展X射线吸收精细结构（EXAFS）分析，作者识别出特定的Al-Co-Cr-Fe-Ni成分，其表现出优异的钝化与自愈合行为，并将Ni-Al短程有序结构与耐腐蚀性降低相关联。

ABSTRACT

Compositionally complex alloys hold the promise of simultaneously attaining superior combinations of properties, such as corrosion resistance, light-weighting, and strength. Achieving this goal is a challenge due in part to a large number of possible compositions and structures in the vast alloy design space. High-throughput methods offer a path forward, but a strong connection between the synthesis of an alloy of a given composition and structure with its properties has not been fully realized to date. Here, we present the rapid identification of corrosion-resistant alloys based on combinations of Al and Cr in a base Al-Co-Cr-Fe-Ni alloy. Previously unstudied alloy stoichiometries were identified using a combination of high-throughput experimental screening coupled with key metallurgical and electrochemical corrosion tests, identifying alloys with excellent passivation behavior. The alloy native oxide performance and its self-healing attributes were probed using rapid tests in deaerated 0.1 mol/L H2SO4. Importantly, a correlation was found between the electrochemical impedance modulus of the exposure-modified air-formed film and self-healing rate of the CCAs. Multi-element extended x-ray absorption fine structure analyses connected more ordered type chemical short-range order in the Ni-Al 1st nearest-neighbor shell to poorer corrosion resistance. This report underscores the utility of high throughput exploration of compositionally complex alloys for the identification and rapid screening of a vast stoichiometric space.

研究动机与目标

• 快速探索Al-Co-Cr-Fe-Ni成分复杂合金的广阔成分空间，以提升耐腐蚀性。
• 弥合复杂合金体系中高通量筛选与高保真度性能验证之间的差距。
• 识别在酸性环境中表现出优异钝化与自愈合行为的特定化学计量比。
• 利用EXAFS分析，将原子尺度的化学短程有序结构与宏观耐腐蚀性能相关联。

提出的方法

• 采用高通量组合式薄膜沉积技术，快速合成广泛的Al-Co-Cr-Fe-Ni成分。
• 利用电化学阻抗谱（EIS）测量空气中形成的氧化膜模量，并评估在脱气0.1 mol/L H2SO4中的自愈合动力学。
• 采用多元素扩展X射线吸收精细结构（EXAFS）分析，探测局部原子结构，特别是Ni-Al一阶最近邻配位情况。
• 快速电化学测试，以在受控条件下评估钝化行为与膜层稳定性。
• 将EIS测得的膜模量与自愈合速率相关联，建立结构-性能关系。
• 采用高保真度验证，确认高通量筛选中观察到的耐腐蚀性趋势。

实验结果

研究问题

• RQ1 在Al-Co-Cr-Fe-Ni体系中，哪些含Al-Cr的成分在酸性环境中表现出最有效的钝化与自愈合？
• RQ2 天然氧化膜的电化学阻抗模量与成分复杂合金的自愈合速率之间有何关联？
• RQ3 Ni-Al化学短程有序在决定CCAs耐腐蚀性方面起何种作用？
• RQ4 高通量筛选能否可靠预测复杂多主元合金中的高保真度耐腐蚀性能？
• RQ5 如EXAFS揭示的局部原子结构变化，如何影响宏观电化学行为？

主要发现

• 特定的Al-Co-Cr-Fe-Ni成分在脱气0.1 mol/L H2SO4中表现出卓越的钝化行为与高自愈合速率，表明其具有强耐腐蚀性。
• 观察到电化学阻抗模量与自愈合速率之间存在强烈正相关关系，表明膜稳定性决定愈合能力。
• EXAFS分析显示，Ni-Al一阶最近邻壳层中有序度增加与耐腐蚀性降低相关，提示存在有害的局部原子构型。
• 本研究证明，高通量筛选可有效缩小复杂合金体系中具有前景的候选成分范围，以供高保真度验证。
• 所识别的合金表现出稳定的天然氧化膜，具有高阻抗，表明其具有坚固的钝化层形成能力并能抵抗破裂。
• 将高通量筛选与高保真度电化学及结构分析相结合，实现了对耐腐蚀CCAs的快速、数据驱动式发现。