纳米晶体合金的氧化行为
Yashaswini Karanth1, Saurabh Sharma1, Kris Darling2
1School for Engineering of Matter, Transport, and Energy, Arizona State University, Tempe, AZ 85287, USA.
Materials (Basel, Switzerland)
|December 17, 2024
概括
纳米晶体合金提供强度,但面临氧化风险. 添加特定元素可以创建保护,增强高温氧化耐受性,适用于苛刻的应用.
科学领域:
- 材料科学 材料科学 材料科学
- 金工业是金工业的一个方面.
- 氧化和腐蚀的作用
背景情况:
- 纳米晶体 (NC) 合金提供优越的机械强度和高温稳定性.
- 然而,它们的细粒度结构增加了由于增强的粒度边界 (GB) 扩散而导致内部氧化的易感性.
- 热生长氧化物 (TGO) 可以通过作为扩散障碍来减轻这种脆弱性.
研究的目的:
- 审查耐氧化NC合金的进展情况.
- 检查颗粒大小,合金化学和氧化行为之间的相互作用.
- 探索开发具有改善氧化抵抗力的微结构稳定的NC合金的策略.
主要方法:
- 分析谷物精炼对扩散系数的影响 (例如,Ni-Cr合金中的Ni和Cr).
- 研究第三元素和反应性元素 (Hf,Zr,Y) 作为氧吸收物和TGO形成物.
- 包括传输电子显微镜 (TEM),扫描电子显微镜 (SEM) 和能量散射X射线光谱 (EDS) 在内的特征技术用于氧化物尺度可视化.
主要成果:
- 在Ni-Cr和Cu-Cr等NC合金中精细化谷物可以通过影响GB扩散来改善氧化抵抗.
- 反应性元素促进早期TGO的形成,作为扩散障碍物,增强像NiAl.Al.这样的合金中的氧化阻力.
- 粒径大小,固态度和扩散的结合作用导致氧化质量增加减少和氧化物稳定.
结论:
- 在NC合金中,氧化阻力受到颗粒大小和战略合金化学的显著影响.
- 对于缓解内部氧化和保持结构完整性而言,TGO的形成至关重要.
- 未来的研究应该专注于多溶液策略和对坚固,耐氧化NC合金的表面修改.
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