DMREF/Collaborative Research: Multiscale Alloy Design of HCP Alloys via Twin Mesh Engineering

密堆积（HCP）金属如镁和钛具有提供前所未有的机械性能组合的潜力。然而，HCP金属在工程设计中的成功应用受到其有限塑性的阻碍。 最近的研究结果介绍了令人兴奋的潜力的方法称为“双网工程”。其可用于在HCP金属中诱导同时强化和韧化。这个设计材料革命和工程我们的未来（DMREF）奖支持基础研究，制定设计双网格所需的科学框架。综合实验和建模研究活动将寻求发现合金化是否可以用于为高强度，高韧性HCP合金创建正确的孪生网格。由此产生的材料将在节能制造中具有应用，其中需要具有高强度，低密度，室温成形性和成本竞争力等属性的材料。该奖项将支持加州大学圣巴巴拉分校、欧文分校和戴维斯分校之间的研究合作，以探索HCP金属（如镁和钛）中滑移和孪晶之间的相互关系。由于细滑往往会加剧FCC金属中的孪晶，本研究的目标之一将是评估合金元素对滑移模式的影响，实验和计算使用第一原理。在辨别出容易孪生的成分后，将通过计算评估能够在多晶样品中形成3-D孪生网格的纹理。由于滑移和孪晶同时发生，因此孪晶网格将阻止滑移和孪晶，从而导致强化和韧性。从这项研究中产生的知识将被用来创建一个多尺度工具包，称为双网格模块（TMM），当完全运行时，将协调有关滑移双和双双相互作用，加工，双网格微观结构演变和性能的计算。经过实验验证的TMM将通过提供加工途径的指导来加速HCP合金的材料发现和设计，以创建符合工业实践的3D孪生网格。这一进展沿着材料开发连续体，将导致低密度、高强度、高韧性合金的广泛使用，从而减轻重量和降低燃料消耗。

Hexagonal close packed (HCP) metals such as magnesium and titanium have the potential to provide unprecedented combinations of mechanical properties. Successful incorporation of HCP metals into engineering designs is, however, hindered by their limited plasticity. Recent research results have introduced the exciting potential of an approach termed "twin mesh engineering". which can be applied to induce simultaneous strengthening and toughening in HCP metals. This Designing Materials to Revolutionize and Engineer our Future (DMREF) award supports fundamental research to formulate the scientific framework required to design twin meshes. The integrated experimental and modeling research activities will seek to discover if alloying can be used to create the right twin mesh for high strength, high toughness HCP alloys. The resulting materials will have applications in energy efficient manufacturing where materials with attributes such as high strength, low density, room-temperature formability and cost competitiveness are required. A diverse group of student researchers will participate in the research program at both the graduate and undergraduate levels.This award will support a research collaboration between the Universities of California at Santa Barbara, Irvine and Davis to explore interrelationships between slip and twinning in HCP metals, such as magnesium and titanium. As fine slip tends to accentuate twinning in FCC metals, one of the goals of this research will be to evaluate the influence of alloying elements on slip patterns, both experimentally and computationally using first principles. After discerning compositions that twin readily, textures that enable the formation of 3-D twin meshes in polycrystalline samples will be assessed computationally. Since slip and twinning occur concomitantly, twin meshes will block both slip and twins, leading to strengthening and toughness. The knowledge generated from this research will be used to create a multiscale tool kit, called the twin-mesh module (TMM), which when fully operational will coordinate calculations pertaining slip-twin and twin-twin interactions, processing, twin-mesh microstructure evolution, and properties. Experimentally validated TMM will accelerate materials discovery and design of HCP alloys by providing guidance on processing pathways to create 3-D twin meshes that are consistent with industrial practices. This advancement along the Materials Development Continuum will lead to expanded use of low-density, high strength, high toughness alloys, reducing weight and fuel consumption.