Plasticity enhancement by engineered defect's architecture and concurrent electron-transport properties in Mg-based alloys.

这项研究的主要目的是对纯镁和部分镁合金在塑性变形过程中产生的晶格缺陷的性质以及这些缺陷对力学和电子传输性能的影响有一个基本的了解。这些知识对于为不同应用开发具有优异性能的低成本镁合金的设计和制造中的创新解决方案是必要的。拟议计划的目标是针对镁和镁合金中结构-性能关系的一些方面，这些方面需要很好的理解，但以前从未研究过或解决得不够充分。这些包括：(I)了解晶格缺陷的结构和性质，在孪生过程中，变形孪晶继承了母体的晶格缺陷，以及各种晶格缺陷并入孪晶晶格的机制。这项研究将有助于了解形变孪晶在塑性和断裂中的作用，以及孪晶对镁和镁合金物理性能的影响。(Ii)了解指导制造工艺设计的原则，以开发具有最佳强度和延展性的优化缺陷结构。(Iii)了解存在晶格缺陷和溶质原子时的电子传输，外加磁场对电子传输的影响，以及宏观流动应力和电导率之间的关系。这些目标将通过实验方法和理论研究来实现。这一研究将有助于更好地了解晶体缺陷的原子结构和性质，缺陷存在时电子输运的本质，以及缺陷对镁合金功能性能的影响。该计划强调了变形孪生与机械和电磁场性能之间的联系，因为缺少这方面的知识，但它对于设计合金成分和实现合金优异功能性能的加工路径至关重要。上述前两个目标的进展将为在航空航天、军用航空系统、直升机和汽车工业中应用的具有优异机械性能的镁合金的开发和组织设计提供指导。了解晶格缺陷对电子输运的影响，将有助于指导民用航空和军事航天系统电子工业用镁基材料的发展，这些领域需要轻质、坚固、耐用的材料来屏蔽电磁干扰和辐射防护。在拟议的计划过程中将开发的基本知识可以转移到其他HCP工程合金上。

The broad aim of the proposed research is to develop a fundamental understanding of the properties of lattice defects produced during plastic deformation of pure Mg and selected Mg-alloys and the influence of these defects on mechanical and the electron-transport properties. This knowledge is necessary to develop innovative solutions in the design and fabrication of low-cost Mg-alloys with superior properties for different applications. The objectives of the proposed program target the aspects of the structure-property relationship in Mg and Mg alloys that demand a good understanding, but have never been studied before or have been addressed insufficiently. These include: (i) understanding the structure and properties of lattice defects, which are inherited by deformation twins form the parent during the twinning process and the mechanisms by which various lattice defects are incorporated into the twin lattice. The study will permit to understand the role of deformation twins in plasticity and fracture and the effect of twins on the physical properties of Mg and Mg alloys. (ii) understanding the principles that would guide the design of the fabrication process for the development of the optimized defect architecture, which delivers a superior combination of strength and ductility.(iii) understanding the electron-transport in the presence of lattice defects and solute atoms, the influence of applied magnetic field on the electron-transport and the relationship between macroscopic flow stress and electrical conductivity.The objectives will be achieved by employing experimental methods and theoretical studies. The research will allow gaining a better fundamental understanding of the atomic structure and properties of crystal defects, the nature of the electron transport in the presence of defects, and their influence on functional properties of Mg alloys. The program highlights the link between deformation twinning and the mechanical and galvanomagnetic properties because this knowledge is missing, but it is crucial in designing alloy composition and the processing path for achieving superior functional properties of the alloys. The progress in first two objectives above will provide guidance for the development and microstructural design of Mg alloys with superior mechanical properties for applications in aircraft and space industry, military air systems, helicopters and automotive industry. The understanding of electron transport in the presence of lattice defects will help to guide the development of Mg-based materials for the electronic industry in civil air and military space systems, where the lightweight, strong and durable materials are required for electromagnetic interference shielding and radiation protection. The fundamental knowledge that will be developed during the course of the proposed program is transferable onto other HCP engineering alloys.