GOALI: Ternary Metal Diboride Coatings with Enhanced Oxidation Resistance and Durability - Understanding Phase Formation from a Metastable Starting State

非技术描述：该项目解决了在从微电子到制造业保护涂层的广泛应用中扩展耐高温磨损材料性能的需求。这种涂层对于确保组件质量和可靠性至关重要，可以减少制造缺陷，减少使用中损坏，延长组件在现场和制造过程中的使用寿命，所有这些都将在很大程度上消除浪费，低效操作和资源密集型冗余。改进的涂层也可以扩大设计空间，使工程师能够做出更可持续的选择，或者可以提高性能，但现有技术无法做到这一点。过渡金属二硼化物具有优异的耐磨性和耐高温性能；然而，在这些服务环境中，氧气的存在削弱了这些特性。这项研究将处理科学与最先进的表征工具相结合，以开发二硼化物家族中的新涂层化学物质，这些化学物质可以在氧化环境中保护自己。此外，该加工路线使用化学安全的前体，并在较低的温度下操作，使其成为许多现有涂层技术的可持续替代方案。通过与工业合作伙伴UES公司合作，通过GOALI计划，该研究将重点放在工业领域的理解和技术差距上。研究生研究人员也从这种密切的伙伴关系中受益，通过直接与UES研究人员合作，获得宝贵的培训和专业技能。这些研究生将很好地定位于加入依赖于这些保护涂层的广泛行业的公司（例如，汽车，微电子，航空航天，发电，模具等），这些行业非常需要这些涂层。通过有针对性地招募来自伊利诺伊大学支持工程中代表性不足群体（SURGE）计划的研究生和来自伊利诺伊学者本科研究（ISUR）计划的本科生研究人员，正在培养代表性不足群体的教学、培训和参与。技术细节：本研究的总体目标是建立一个新的可持续的动力学路线的科学基础，以实现耐用，抗氧化的HfAlxBy和HfCrxBy难熔二硼化物薄膜。初始亚稳态是通过低温化学气相沉积和使用化学安全（无卤素）前驱体建立的。pi致力于可持续合成路线，特别是联合pi是UI （http://EaSE.Illinois.edu）“能源与可持续工程”研究生证书和孟学位课程的联合创始人和首席讲师。一旦制作完成，薄膜的性能将在沉积和退火条件下使用定量技术进行评估，包括透射电子显微镜、电子能量损失光谱和能量色散x射线光谱。然后根据合成过程中各组分步骤的动力学模型分析了薄膜生长、微观结构和组成的结果。此外，在探索性工作中，使用合作者开发的Cr(B3H8)2前体来检查Cr的掺入。该前驱体除氢外不含杂原子，已被co-PI证明可沉积高质量的CrB2薄膜，因此，它有望与Hf(BH4)4结合良好。薄膜的生长，包括化学安全合成路线的追求和验证，分析和测试都积极参与到GOALI合作伙伴UES Inc.的工作中，通过定期沟通和人员之间的长期访问来促进。然后将成功的协议转移到工业中。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

NON-TECHNICAL DESCRIPTION: This project addresses the need to expand the performance of materials that resist wear at elevated temperatures in a wide range of applications from microelectronics to protective coatings for manufacturing. Such coatings are critical for ensuring component quality and reliability by reducing manufacturing flaws, reducing in-service damage and extending the lifetime of components in the field and in manufacturing processes - all of which will largely eliminate waste, inefficient operations and resource intensive redundancies. Improved coatings may also expand the design space, allowing engineers to make choices that are more sustainable or could improve performance but are otherwise impossible with existing technologies. Transition metal diborides have exceptional wear properties and are quite tolerant of high temperatures; however, the presence of oxygen in these service environments diminishes those properties. This research is coupling processing science with state of the art characterization tools to develop new coating chemistries in the diboride family that evolve to protect themselves in oxidizing environments. Moreover, the processing route uses chemically safe precursors and operates at lower temperatures, making it a sustainable alternative to many existing coating technologies. By engaging an industrial partner, UES Inc., though the GOALI program, this research is focused on industrially identified gaps in understanding and technology. Graduate student researchers are also benefiting from this close partnership, gaining invaluable training and professional skills by working directly with UES researchers. These graduate students will be well positioned to join companies across a wide spectrum of industries dependent on these protective coatings (e.g., automotive, microelectronics, aerospace, power generation, tooling, etc.) where they are very much in demand. Teaching, training and participation of underrepresented groups is being fostered through targeted recruitment of graduate students from the University of Illinois Support of Under-Represented Groups in Engineering (SURGE) program and undergraduate researchers from the Illinois Scholars Undergraduate Research (ISUR) program.TECHNICAL DETAILS: The overarching objective of this study is to establish the scientific underpinnings of a new sustainable kinetic route towards durable, oxidation resistant refractory diboride thin films of HfAlxBy and HfCrxBy. The initial metastable state is established through low temperature chemical vapor deposition and the use of chemically safe (halogen free) precursors. The PIs are committed to sustainable synthesis routes, specifically the co-PI is a co-founder and lead instructor in the 'Energy and Sustainability Engineering' graduate certificate and MEng degree programs at UI (http://EaSE.Illinois.edu). Once fabricated, film properties are evaluated in both as-deposited and annealed conditions using quantitative techniques, including transmission electron microscopy, electron energy loss spectroscopy, and energy dispersive X-ray spectroscopy. The results for film growth, microstructure and composition are then analyzed in terms of kinetic models for the component steps in the synthesis process. Additionally, in exploratory work, incorporation of Cr is examined using the Cr(B3H8)2 precursor developed by a collaborator. This precursor, which contains no heteroatoms other than hydrogen, has previously been demonstrated by the co-PI to deposit high quality CrB2 films, hence, it is expected to work well in combination with Hf(BH4)4. Film growth, including the pursuit and validation of chemically safe synthesis routes, analysis and testing actively involve the GOALI partner, UES Inc., facilitated by regular communication and extended visits of personnel between sites. Successful protocols are then transferred to industry.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.