Li Congcong, Zheng Wenjin, Zhong Haonan, Liu Xiongjun, Zhu Huihui, Wang Hui, Wu Yuan, Zhang Xiaobin, Yu Zhiyang, Jiang Suihe, Lu Zhaoping
State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing, PR China.
Institute of Materials Intelligent Technology, Liaoning Academy of Materials, Shenyang, Liaoning, PR China.
Nat Commun. 2025 Mar 7;16(1):2291. doi: 10.1038/s41467-025-57635-7.
An intact oxide scale adhering well to the matrix is crucial for the safe service of metallic materials at high temperatures. However, premature failure is usually caused by spallation of scales from the matrix. Although few mechanisms have been proposed to understand this phenomenon, consensus has not yet been reached. In this study, we reveal that trace sulfur impurities contaminated in high-purity raw materials prominently segregate to the interface and form a thin intermediate amorphous-like layer between the oxide scale and alloy matrix during the oxidation process. Subsequently, cracking and spallation occur preferentially between the sulfur-rich layer and alumina scale due to the weak bonding between sulfur and alumina atoms. We validate the revealed atomistic spalling mechanism by successfully eliminating the detrimental effect of sulfur via microalloying. Our findings are useful for improving adhesion of oxide scales and enhancing heat-resistant properties of other high-temperature alloys.
完整且与基体紧密结合的氧化皮对于金属材料在高温下的安全服役至关重要。然而，过早失效通常是由氧化皮从基体上剥落引起的。尽管已经提出了一些机制来解释这一现象，但尚未达成共识。在本研究中，我们发现高纯度原材料中污染的微量硫杂质显著偏析到界面处，并在氧化过程中在氧化皮和合金基体之间形成一层薄的类似非晶的中间层。随后，由于硫与氧化铝原子之间的弱键合，富硫层与氧化铝氧化皮之间优先发生开裂和剥落。我们通过微合金化成功消除了硫的有害影响，验证了所揭示的原子剥落机制。我们的研究结果有助于提高氧化皮的附着力，并增强其他高温合金的耐热性能。
