Self Repairable Seals by Crack Healing of Glass and Glass-Ceramic Composites for Solid Oxide Fuel Cells

这项资助的主要目的是建立对有前途的玻璃和玻璃陶瓷复合材料裂纹愈合机制的基本理解，这有助于推进燃料电池自修复密封的变革概念。玻璃被用作固体氧化物燃料电池（sofc）的密封件，用于直接发电。它需要在800°C下工作的密封金属陶瓷密封，这是具有挑战性的，并且在操作过程中容易发生玻璃密封开裂。为了应对这一挑战，一种由表面能量驱动的主动自修复密封的新概念将被开发出来。这个新概念背后的基本原理是，在800°C的SOFC工作温度下，具有适当表面和热物理特性的密封玻璃可以愈合或修复热瞬变过程中产生的裂缝。然而，目前对玻璃和玻璃陶瓷复合材料裂纹愈合的动力学和机制还缺乏基本的认识。有了这样的理解，人们就可以识别裂缝愈合/自我修复机制，并能够预测在功能SOFC中实现自我修复所需的愈合时间。此外，通过玻璃结晶或有意添加以影响裂纹愈合行为而产生的结晶陶瓷相的作用将得到更好的理解，以便设计具有最佳承载能力和自修复性的玻璃陶瓷复合材料，用于SOFC中的密封。通过这笔拨款，PI还将开发分析模型来描述和预测实验观察到的裂缝愈合和自我修复行为。密封件在sofc、真空技术、微电子、电力电子和微机电系统等多个高科技领域发挥着关键作用。拟议中的研究将为研究生、本科生和博士后提供宝贵的技术和研究技能，适用于学术界和工业界，并通过为高科技应用合成玻璃和玻璃复合材料的新设施来增加我们机构的资源。此外，由于目前的重点是节约有限的自然资源用于能源生产，高效的SOFCs将通过降低发电的燃料消耗和对环境的影响，直接节省能源。少数民族/女性本科生和高中生将通过多元文化工程项目（MEP）和WEAT（工程、建筑和技术领域的女性）项目接受指导并接触到这项研究。通过ASM材料研讨会和为教师和学生举办的营地，我们向高中提出了一个重要的扩展。

The primary objective of this grant is to establish a fundamental understanding of the crack-healing mechanism in promising glasses and glass-ceramic composites useful for advancing a transformative concept of self-repairable seals for fuel cells. Glasses are used as seals in solid oxide fuel cells (SOFCs) for generating electricity directly. It requires hermetic metal-ceramic seals functioning at 800°C, which is challenging and susceptible to glass seal cracking during operation. To address this challenge, a novel concept of active self-repairable seals driven by surface energy will be pursued. The rationale behind this novel concept is that at the SOFC operating temperature of 800°C a sealing glass with appropriate surface and thermophysical properties can heal or repair cracks created during thermal transients. However, a fundamental understanding of the kinetics and mechanism of crack healing in glasses and glass-ceramic composites is currently lacking. With such an understanding, one can identify the crack-healing/self-repair mechanism and be able to predict the healing time required for achieving self-repair in a functioning SOFC. In addition, the role of the crystalline ceramic phase created either by crystallization of the glass or added intentionally for influencing crack healing behavior will be better understood so that the glass-ceramic composites with optimum load-bearing capability and self-repairability can be designed for use as seals in a SOFC. Through this grant, the PI also will develop analytical models to describe and predict crack-healing and self-repair behaviors observed experimentally.Seals play a critical role in several high-technology areas including SOFCs, vacuum technology, microelectronics, power electronics, and microelectromechanical systems. The proposed research will train graduate and undergraduate students and postdoctoral associates in invaluable technical and research skills applicable to both academia and industry and advance the resources of our institution by new facilities for the synthesis of glasses and glass-composites for high-technology applications. In addition, with the current emphasis on conserving our limited natural resources for energy production, efficient SOFCs will result in direct savings by lower fuel consumption for power generation and environmental impact. The minority/women undergraduate and high school students will be mentored and exposed to this research through Multicultural Engineering Program (MEP), and WEAT (Women In Engineering, Architecture & Technology) programs. A significant outreach to high schools is proposed through ASM materials workshops and camps for teachers and students.