Failure Mechanics of 2D Materials for Advanced Coatings and Composites

二维（2D）材料已经成为一类新的材料，有望对从航空航天结构到能源存储等关键应用产生颠覆性的变化。在过去的十年里，研究人员已经证明了单个二维纳米结构的非凡的电学、热学和机械性能，最著名的是石墨烯，然而，成功地将其结合到大规模的材料和设备中仍然是难以捉摸的。特别是，二维材料具有非常高的强度和刚度，以及非常低的摩擦，使其成为复合材料中非常理想的涂层和增强材料。尽管前景广阔，但材料的宏观性能受到关键缺陷和暴露于循环载荷或界面滑动时的抗破坏能力的限制。虽然过去十年二维材料的纳米力学研究主要集中在阐明内在力学特性（即强度、模量、摩擦），但下一波的深入研究需要研究其工程相关的失效特性，包括断裂韧性、疲劳寿命和磨损行为。拟议的研究计划旨在弥合最有前途的二维纳米材料及其在实际机械应用（即涂层和复合材料）中的实现之间的差距，通过扩展对其内在机械行为的基本理解，包括工程相关特性（即断裂韧性，疲劳，磨损），从而能够在存在关键缺陷和循环加载/滑动的情况下预测材料失效。该计划将采用多尺度方法，将最先进的实验纳米力学测试和纳米尺度的原子建模与微观和宏观的最终使用材料测试和连续体建模相结合。该计划将分为三个重点领域；1)功能化和非功能化二维材料的断裂韧性研究，2)二维材料的疲劳循环失效和寿命研究，3)磨损状态下二维材料的摩擦学（摩擦磨损）研究。该研究项目将弥合与宏观涂层和复合材料中二维材料集成相关的机械失效现象的基本理解的关键差距。在三个推力区域内的研究将为二维材料的破坏力学领域提供一个新的知识体系。这最终将导致涂料和复合材料性能的前所未有的进步，这将使加拿大在航天/航空航天、汽车和能源存储领域的公司和组织受益。它将在跨学科的培训环境中直接支持高素质人才的培训，这将利用独特的原位纳米力学研究基础设施和国际合作。

Two dimensional (2D) materials have emerged as a new class of materials that are expected to make disruptive changes to critical applications ranging from aerospace structures to energy storage. In the last decade researchers have demonstrated the extraordinary electrical, thermal, and mechanical properties of individual 2D nanostructures, most notably graphene, however the successful incorporation into largescale materials and devices remains elusive. In particular, 2D materials are know to exhibit extraordinarily high strength & stiffness as well as extraordinarily low friction making them highly desirable as coatings and reinforcements in composite materials. Despite this great promise, macroscopic materials behavior is limited by the ability to resist failure in the presence of critical defects and exposure to cyclic loading or interfacial sliding. While the last decade of nanomechanics research of 2D materials has focused on elucidating intrinsic mechanical properties (i.e. strength, modulus, friction), a next wave of intense research is needed to study their engineering relevant failure properties including fracture toughness, fatigue life, and wear behavior. The proposed RESEARCH PROGRAM aims to bridge the gap between the most promising 2D nanomaterials and their implementation in practical mechanical application (i.e. coatings & composite materials) by extending the fundamental understanding of their intrinsic mechanical behavior to include engineering relevant properties (i.e. fracture toughness, fatigue, wear) that enable prediction of materials failure in the presence of critical defects and cyclic loading/sliding. The program will employ a multiscale approach which combines state of the art experimental nanomechanical testing and atomistic modeling at the nanoscale with micro and macroscopic end use materials testing and continuum modeling. The program will be divided into three thrust areas; I) fracture toughness studies of functionalized and unfunctionalized 2D materials, II) fatigue cyclic failure and lifetime studies of 2D materials and III) tribology (friction & wear) studies of 2D materials in the wear regime. The research program will bridge critical gaps in the fundamental understanding of mechanical failure phenomena relevant to the integration of 2D materials within macroscopic coating and composite materials. The studies within the three thrust areas will provide a new body of knowledge in the area of failure mechanics of 2D materials. This will ultimately lead to unprecedented advancements in coating and composite materials performance which will benefit Canadian companies and organizations in space/aerospace, automotive, and energy storage sectors. It will directly support the training of highly qualified personnel within an interdisciplinary training environment which will leverage unique in situ nanomechanics research infrastructure and international collaboration.