Development of an electron work function-based novel methodology for designing advanced tribo-materials

材料科学与工程在开发改进材料以增强抗失效能力的理论和方法方面有着悠久的历史。微结构工程在材料设计中起着至关重要的作用。然而，微观结构特征并不总是为剪裁材料提供明确的线索。随着不仅在通常条件下，而且在极端条件下的应用需求的增加，材料设计需要依赖于更基本的原则。该项目旨在开发结构材料设计的新方法，重点是在可行的电子基础上的摩擦材料。材料的内在性质从根本上取决于它们的电子行为，电子行为决定了原子键的强度和延展性。长期以来，人们一直致力于基于量子力学将材料的力学性能与其电子状态相关联，然而，将其用于结构材料设计是复杂的。人们迫切希望得到简单而基本的参数，这些参数反映了材料的电子行为，以便以可行的方式进行材料分析和设计。申请人的小组已经对电子功函数（EWF）进行了广泛的研究，并证明EWF与许多材料性质相关，并且是用于指导剪裁材料的有希望的指标。然而，材料性能不仅取决于材料中各个相和晶粒的性能，还取决于其微观结构。当具有不同EWF的多晶材料中的第二相接触时，存在电子转移以建立热力学平衡。这些影响EWF分布，从而影响整体性能。因此，了解微观结构成分如何影响整体EWF及其与整体或整体材料性能的关系，对开发新的实际材料设计方法具有重要意义。这是在这个新的发现项目中提出的研究的主要目标或 * 长期目标，* 这与申请人以前的发现项目不同，后者专注于EWF与纯金属和均匀 * 固溶体性质之间的 * 相关性。研究内容包括：1）研究显微组织成分，包括晶粒尺寸、取向、晶界和第二相（尺寸、形貌、性质和界面），影响多晶多相材料的局部和全局EWF; 2）EWF与多相材料性能的相关性研究，为EWF的开发提供了理论依据。基于材料设计和剪裁的方法或方法，重点是摩擦材料。*

Materials science and engineering have a long history of developing theories and approaches to improve materials for enhanced resistance to failure. Microstructure engineering plays a crucial role in material design. However, microstructural features do not always provide clear clues for tailoring materials. With increased demands for applications under not only usual conditions but also extreme ones, material design has been required to rely on more fundamental principles. This project is proposed to develop new methodologies for structural material design with emphasis on tribo-materials on a feasible electronic base. Intrinsic properties of materials are fundamentally determined by their electron behavior, which governs the atomic bond strength and ductility. Great effort has long been made to correlate mechanical properties of materials to their electron state based on quantum mechanics, which is, however, complicated to be used in structural material design. It is highly desired to have simple but fundamental parameters, which reflect the electron behavior of materials, for material analysis and design in a feasible manner. The applicant's group has conducted extensive studies on electron work function (EWF) and demonstrated that EWF is correlated to many material properties, and is a promising indicator for guiding tailoring materials. However, material properties are dependent not only on properties of individual phases and grains in a material but also its microstructure. When second phases in polycrystalline materials with different EWFs are in contact, there exists electron transfer in order to establish thermodynamic equilibrium. These affect EWF distribution and thus overall performance. Thus, it is of significance to understand how microstructural*constituents influence the overall EWF and its relationships with the*overall or global material properties towards the development of new*methodologies for realistic material design. This is the main goal or*long-term objective of research proposed in this new Discovery project,*which is distinct from that of applicant's previous Discovery project, which was focused on the*correlation between EWF and properties of pure metals and homogeneous*solid solutions. The followings will be included in the project: 1) studies on how microstructural constituents, including grain size, orientation, grain boundaries, and second phases (size, morphology, properties and interface), influence local and global EWFs of polycrystalline multiphase materials; and 2) studies on the correlation between EWF and properties of the multi-phase materials towards development of EWF-based approaches or methodologies for material design and tailoring with focus on tribo-materials.***********