EAGER: Controllable Synthesis of Gradient-Microstructured Materials, from the Nanoscale to Macroscale

纳米结构材料是指表面具有纳米结构，而芯部具有较粗结构的材料。这种材料已经证明了与具有均匀粗晶粒或纳米晶体结构的材料相比令人印象深刻的机械性能优势。然而，迄今为止，尚未实现制造用于商业用途的梯度结构材料的能力。该奖项支持对控制薄膜和块状材料微结构的工艺参数进行更深入的科学理解的研究，特别是EARLY概念探索性研究（EAGER）奖将支持这些新型梯度结构的制造和合成的演示。制造这些结构的能力将允许对它们的行为进行科学研究，从这项研究中获得的新知识将使工程材料的设计具有更好的耐磨性和耐腐蚀性，并且还大大提高了屈服强度和韧性。这项工作的好处将体现在提高性能和产品寿命的零部件受到极端的工程环境中的汽车，航空航天和机床industry.The早期阶段的工作的研究目标是探索新的加工方法，以获得材料的可控晶粒尺寸梯度。为了实现可控的晶粒尺寸梯度在薄膜和散装样品的目标，将进行两种处理方法的系统调查，与理解如何处理参数可以与梯度微观结构演变的具体目标。这些任务包括溅射制造的梯度钛薄膜定制层厚度，粒度梯度，和梯度界面，和表面机械磨损处理的钛通知微观结构细化的数值模型。从这项研究中产生的科学见解将提供一个更清晰的画面上的梯度微结构材料的微结构演变的加工条件的影响，并促进梯度纳米结构材料，这可能会加速插入到未来的结构和涂层应用的可用属性空间的更好的理解。

Gradient-structured materials are materials which have nanometer sized structure at the surface, and coarser structure at the core. Such materials have demonstrated impressive mechanical performance advantages over materials with homogeneous coarse-grained or nanocrystalline structures. So far, however, the ability to manufacture gradient structured materials for commercial use has not yet been realized. This award supports research to develop deeper scientific understanding of processing parameters that control the microstructures in both thin film and bulk materials, and in particular this EArly-concept Grant for Exploratory Research (EAGER) award will support demonstration of the fabrication and synthesis of these novel gradient structures. The ability to fabricate these structures will allow for scientific investigation of their behavior, and the new knowledge gained from this research will enable the design of engineered materials with improved resistance to wear and corrosion, and also drastically improved yield strength and toughness. The benefits of this work will manifest in improved performance and product lifetimes for components subjected to extreme engineering environments in automotive, aerospace and machine tools industries.The research objective of this early-stage work is to explore novel processing approaches for obtaining materials with controllable grain size gradients. To realize the goal of controllable grain size gradients in both thin-film and bulk samples, a systematic investigation of two processing approaches will be carried out, with the specific goal of understanding how processing parameters can be correlated with gradient microstructural evolution. These tasks include sputtering fabrication of gradient titanium thin-films with tailored layer thicknesses, grain size gradients, and graded-interfaces, and surface mechanical attrition treatment of titanium informed by numerical models of microstructural refinement. The scientific insights stemming from this research will provide a clearer picture on the effect of processing conditions on the microstructural evolution of gradient microstructure materials, and facilitate a better understanding of the property space available for gradient nanostructured materials, which may accelerate insertion into future structural and coating applications.