Developing deformation maps for designing nanoporous metals with enhanced ductility and strength

非技术摘要纳米多孔(NP)金属是由相互连接的孔和韧带组成的三维网络。它们的开孔结构和单位体积的高比表面积使它们具有独特的电、机械和催化性能。这些特性使NP金属成为各种高科技应用的极佳候选者，包括用于燃料电池、气体过滤、生物传感器和执行器的催化剂。NP结构在所有这些应用中的性能都与其在运行过程中的力学性能和变形行为有关。例如，由于缺乏应变硬化，Np Au的宏观塑性有限。在许多应用中，特别是在循环载荷下，NP-Au的脆性断裂会损害其相互连接的结构，并导致功能损失。该项目将使用计算模拟方法来研究纳米多孔金结构的变形行为，并确定在结构和功能应用中使NPAu表现出延展性和高强度的微结构条件。这些结果将与现有的关于NP-Au力学行为的实验研究相比较。该项目将有助于该地区学生的教育，国际和平研究所将鼓励来自代表性不足的群体的学生在STEM领域追求职业生涯。技术摘要拟议的项目将开发数学模型和变形图，使纳米孔金(NP Au)的设计具有更好的机械性能。研究小组将测试这一假设，即改变NP Au的形态构型可以增强其延展性和强度。为了实现这一目标，将进行原子水平的模拟，以了解控制Np-Au塑性变形的潜在机制。结构和形态参数的作用，包括表面和界面效应，韧带和孔的大小，取向和加载方向，三重连接的影响，孔和韧带的密度，表面台阶和空洞将被确定。Pi和她的团队将把他们的发现整合到变形图和数学模型中，这些变形图和数学模型将变形机制与结构参数联系起来，并预测导致增强延展性和强度的形态。这些预测将与现有的关于NP-Au力学行为的实验研究相比较。该项目将有助于该地区学生的教育，国际学生协会将鼓励来自代表性不足群体的学生在STEM地区从事职业生涯。

Non-Technical AbstractNanoporous (NP) metals are three-dimensional networks of inter-connected pores and ligaments. Their open-cell structure and high surface area per unit volume give them unique electrical, mechanical, and catalytic properties. These properties make NP metals excellent candidates for a variety of high-tech applications including catalysts for fuel cells, gas filtration, biosensors, and actuators. The performance of NP structure in all these applications is connected to its mechanical properties and deformation behavior during operation. For example, NP Au shows limited macroscopic ductility due to lack of strain hardening. The brittle fracture of NP Au can harm its interconnected structure and cause loss of functionality in many applications especially under cyclic loading. This project will use computational simulation methods to investigate the deformation behavior of nanoporous gold structure and determine the microstructure conditions under which NP Au exhibits ductile behavior and high strength for use in structural and functional applications. These results will be compared with available experimental investigations of the mechanical behavior of NP Au. The project will contribute to the education of students in the area and the PI will encourage students from underrepresented groups to pursue careers in STEM areas.Technical AbstractThe proposed project will develop mathematical models and deformation maps that enable design of Nanoporous gold (NP Au) with improved mechanical properties. The research team will test the hypothesis that varying the morphological configuration of NP Au can enhance its ductility and strength. In pursuit of this goal, atomic-level simulations will be performed to understand the underlying mechanisms that control plastic deformation in NP Au. The role of structural and morphological parameters including surface and interface effects, ligament and pore sizes, orientation and loading direction, effect of triple junctions, density of pores and ligaments, surface ledges, and voids will be determined. The PI and her team will integrate their findings into deformation maps and mathematical models that relate the deformation mechanisms to structural parameters and predict the morphologies that result in to enhanced ductility and strength. These predictions will be compared with available experimental investigations of the mechanical behavior of NP Au. The project will contribute to the education of students in the area and the PI will encourage students from underrepresented groups to pursue careers in STEM areas.