Role of Minor Alloying Elements in the Corrosion of Selected Amorphous Alloys

微量合金元素在选定非晶合金腐蚀中的作用

• 批准号: 0906663
• 负责人: John Scully
• 金额: $ 40.5万
• 依托单位: University of Virginia Main Campus
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-08-15 至 2014-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0906663&HistoricalAwards=false
• 关键词: Role; Minor; Alloying; Elements; Corrosion

TECHNICAL SUMMARY:Traditional methods to obtain excellent corrosion resistance in metallic alloys include addition of metallic and metalloid elements up to the concentrations necessary to either form passivating films, inhibit active dissolution in pits, or reach the ?parting limit? associated with dealloying. Structural and chemical defects have also been affected by controlled alloying additions in heterogeneous materials. Amorphous metals incorporate many of these strategies: structural and chemical heterogeneities are minimized, and metastable supersaturated solid solutions are often formed with large concentrations of beneficial alloying elements. However, the possible beneficial role(s) of minor alloying additions on corrosion resistance are rarely explored. Yet, minor alloying elements offer substantial opportunities to improve the corrosion resistance of many metallic materials. Indeed, this strategy has provided some of the greatest gains in alloy corrosion resistance in the last 100 years. This work will investigate the role of trace beneficial alloying additions in two solid solution systems: amorphous Fe-Cr-Mo-C alloys containing small concentrations of B, Y, W and Si as well as in Al-Cu-Mg alloys containing small amounts of Ni or Pd through systematic additions and nano- as well as micro-meter scale characterization and modeling. Several testable hypotheses exist; some of these will be explored in the proposed work. Minor alloying elements can affect bonding and/or form atomic clusters in the alloy with less noble, corrosion prone alloying elements to alter their otherwise preferential oxidation tendency. High melting temperature, noble minor alloying elements lack surface mobility and these relatively immobile species could block dissolution sites on the surface of dissolving metals. Minor alloying elements could also alter the solute diffusion rates in the oxide or alloy, thus operating as agents that shift alloying element ratios favorably for corrosion resistance.NON-TECHNICAL SUMMARY:Corrosion of engineering materials is an issue of international importance that threatens safety, health, security, needs for clean water and energy independence. The annual cost in the US exceeds 300 billion dollars per year. There is also a growing shortage of newly trained corrosion scientists and engineers connected with the national shortage of engineering graduates. This project not only supports the fundamental understanding necessary for development of enhanced alloys for security and energy applications but also supports human resource development in the area of corrosion science ? a crucial need identified by the National Academy of Sciences. This project provides the venue for the multi-disciplinary knowledge-based education of 2 graduate students in Materials Science and Engineering that will then provide needed professionals in the corrosion-metallurgy field. The Center for Electrochemical Science and Engineering at the University of Virginia trains students in the multi-disciplinary areas of corrosion and materials science/engineering and is a major supplier of professionals with such knowledge to US industry, government, and academia. Under-represented gender and ethnic students are a proven prior and on-going emphasis of this integrated training and research endeavor. Students disseminate scientific results in broad interest papers and books, specialty papers, conferences, short courses and lab tours/demos for K-12 students.

技术总结：传统的方法，以获得优良的耐腐蚀性的金属合金包括金属和非金属元素的添加到必要的浓度，要么形成钝化膜，抑制活性溶解坑，或达到？分型极限？与去合金化有关。结构和化学缺陷也受到非均质材料中受控合金添加剂的影响。非晶态金属结合了许多这些策略：结构和化学不均匀性最小化，亚稳态过饱和固溶体通常与大浓度的有益合金元素形成。然而，很少探索微量合金添加剂对耐腐蚀性的可能有益作用。然而，微量合金元素为改善许多金属材料的耐腐蚀性提供了大量机会。事实上，在过去的100年里，这种策略在合金耐腐蚀性方面取得了一些最大的进步。本工作将研究微量有益合金添加剂在两种固溶体系统中的作用：含有少量B、Y、W和Si的非晶Fe-Cr-Mo-C合金以及含有少量Ni或Pd的Al-Cu-Mg合金，通过系统添加和纳米以及微米尺度表征和建模。存在几个可检验的假设;其中一些将在拟议的工作中进行探讨。微量合金化元素可影响结合和/或在合金中形成原子簇，具有较不贵重的、易腐蚀的合金化元素，以改变它们在其他方面的优先氧化倾向。熔融温度高，贵金属微量合金元素缺乏表面流动性，这些相对不流动的物种可能会阻塞溶解金属表面上的溶解位点。微量合金元素也可以改变氧化物或合金中的溶质扩散速率，从而作为改变合金元素比例的试剂，有利于耐腐蚀性。非技术总结：工程材料的腐蚀是一个国际性的重要问题，威胁着安全，健康，安全，清洁水和能源独立的需求。美国每年的成本超过3000亿美元。与全国工程毕业生短缺有关的新培训的腐蚀科学家和工程师也越来越短缺。该项目不仅支持安全和能源应用增强合金的发展所需的基本理解，而且还支持腐蚀科学领域的人力资源开发。这是美国国家科学院确定的一个关键需求。该项目为2名材料科学与工程研究生的多学科知识教育提供了场所，从而为腐蚀冶金领域提供了所需的专业人才。弗吉尼亚大学电化学科学与工程中心培养腐蚀和材料科学/工程多学科领域的学生，是美国工业，政府和学术界拥有此类知识的专业人士的主要供应商。 代表性不足的性别和民族学生是这一综合培训和研究奋进的一个公认的优先和持续的重点。学生在广泛的兴趣论文和书籍，专业论文，会议，短期课程和实验室图尔斯/演示K-12学生传播科学成果。