CAREER: Effects of Alloy Concentration on the Tribocorrosion Resistance of Al-TM Supersaturated Solid Solutions

事业：合金浓度对 Al-TM 过饱和固溶体耐摩擦腐蚀性能的影响

• 批准号: 1455108
• 负责人: Wenjun Cai
• 金额: $ 54.79万
• 依托单位: University of South Florida
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-05-01 至 2018-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1455108&HistoricalAwards=false
• 关键词: CAREER; Effects; Alloy; Concentration; Tribocorrosion

NON-TECHNICAL DESCRIPTION: Tribocorrosion is a material degradation process caused by the combined effects of wear and corrosion. It is a research area that emerged recently, driven by increased demand for wear- and corrosion-resistant materials from biomedical implants, nuclear power generation, marine and offshore industries, etc. The complexity of tribocorrosion lies in the fact that the chemical and mechanical attacks act synergistically to cause accelerated failure. The synergetic effect is most prominent for passive metals, such as stainless steels, titanium and aluminum alloys, which rely on the presence of a thin surface oxide film (passive film) as a protective barrier against corrosion. When mechanical wear takes place during corrosion, the passive film can be locally destroyed, with the ensuing depassivation leading to rapid corrosion and early component failure. This research seeks to offer insight concerning the degradation mechanisms during tribocorrosion of passive metals using experiments and modeling. The obtained results can lead to the development of new tribocorrosion resistant alloys and coatings with enhanced durability. Research opportunities and a mentorship program are created for undergraduate students and under-represented minorities. Relevant core undergraduate courses are updated to include tribocorrosion-related topics. The outreach program features hands-on demonstrations for girls in elementary and middle schools from Pinellas County, Florida, to stimulate their interest in STEM fields. Published and promoted videos demonstrating the physical concepts related to this research are on popular social media platforms to educate a broad and diverse audience about tribocorrosion. TECHNICAL DETAILS: Al exhibits excellent corrosion resistance but poor scratch resistance, which greatly limits its potential usage in industrial applications where mechanical contact and corrosive environment coexist. Recent studies from our group demonstrates that alloying Al with a transition metal (TM) in supersaturated solid solution has the potential of simultaneously increasing the wear resistance of Al alloys as well as the protectiveness of the passive layer, thus improving the overall tribocorrosion resistance. This research project is directed towards identifying how alloy concentration affects deformation and degradation during tribocorrosion and is centered on a comprehensive study that integrates material processing, characterization, tribocorrosion testing, and theoretical modeling. The proposed processing technique produces materials with various alloy concentrations while minimizing crystallographic texture and residual stress effects. Materials are characterized site-specifically to evaluate the microstructural modifications induced by different degradation mechanisms during tribocorrosion, including wear and corrosion and their synergistic and stochastic aspects. The specific technical objectives include (1) establishment of the alloy concentration/tribocorrosion resistance relationship for Al-TMs, (2) determination of whether an optimum alloy concentration exists for the best tribocorrosion resistance, and (3) investigation of whether (and how) in-service conditions (e.g., applied load, sliding speed) and corrosion conditions influence the tribocorrosion resistance. The obtained results help establish better guidelines for the application of metals in harsh environments and service conditions. The findings also serve to improve design principles for new tribocorrosion-resistant Al alloys, the use of which presents great potential for increasing the sustainability of global energy consumption.

非技术描述：摩擦腐蚀是由磨损和腐蚀的综合作用引起的材料降解过程。这是一个最近出现的研究领域，这是由于生物医学植入物，核发电，海洋和海上行业的耐磨性和耐腐蚀材料的需求增加而驱动的。滴答性腐蚀的复杂性在于化学和机械攻击协同行动的化学和机械攻击行动，从而导致了加速失败。对于被动金属，例如不锈钢，钛和铝合金，这种协同作用最为突出，它们依靠存在薄表面氧化物膜（被动膜）作为防御腐蚀的保护性屏障。当机械磨损期间发生机械磨损时，可以局部破坏被动膜，随之而来的深度活化会导致快速腐蚀和早期组件故障。这项研究旨在通过实验和建模在被动金属互动过程中提供有关降解机制的见解。获得的结果可能导致具有增强耐用性的新型抗腐蚀合金和涂层的发展。研究机会和指导计划是为本科生和代表性不足的少数民族而创建的。相关的核心本科课程已更新，包括与摩擦腐蚀相关的主题。宣传计划由佛罗里达州Pinellas县的小学和中学的女孩进行动手演示，以刺激她们对STEM领域的兴趣。发表和宣传的视频展示了与这项研究相关的物理概念，这是在流行的社交媒体平台上，可以教育广泛而多样的受众关于互动腐蚀。技术细节：AL表现出极好的耐腐蚀性，但抗刮擦性较差，这极大地限制了其在机械接触和腐蚀环境共存的工业应用中的潜在用途。来自我们小组的最新研究表明，在过饱和固体中使用过渡金属（TM）合金AL具有同时提高AL合金的耐磨性以及被动层的保护性，从而提高了整体互动抗性的耐药性。该研究项目旨在确定合金浓度如何影响互动过程中的变形和降解，并以一项综合研究为中心，该研究整合了材料处理，表征，摩擦腐蚀测试和理论建模。提出的加工技术生产具有各种合金浓度的材料，同时最大程度地减少了晶体学质地和残留应力效应。材料的特征是特定于位置的，以评估二聚态腐蚀过程中不同降解机制引起的微结构修饰，包括磨损和腐蚀及其协同和随机方面。特定的技术目标包括（1）建立AL-TMS合金浓度/摩擦式抗性关系，（2）确定是否存在最佳合金浓度以实现最佳的互动抗性，以及（3）研究（以及如何）在服务中（例如）在服务中（例如，施加载荷速度，施加速度）和腐蚀性抗性。获得的结果有助于为在恶劣的环境和服务条件下应用金属的应用建立更好的指南。这些发现还旨在提高抗抗腐蚀性的AL合金的设计原理，其使用具有提高全球能源消耗的可持续性的巨大潜力。