GOALI/Collaborative Research: Design and Optimization of Powder Processed Ni-Base Superalloys via Grain Boundary Engineering

本研究是利用晶界工程技术对具有优异力学性能的高温合金组织进行组织设计。本研究的方法将是开发和连接能够产生具有明显晶界特征的微观组织的过程模型和能够根据微观组织确定疲劳寿命的行为模型。通过基于物理的方法，过程图将镍基高温合金的热变形参数与不同晶界和显微组织的形成联系起来。通过逆向疲劳建模识别出具有优异性能的微结构，并将其制作成散装部件。通过新的原位加载实验，结合应变场测量和取向映射，将确定在不同边界处实现强化的所需机械性能和机制的验证。如果成功，这项研究的好处将包括设计出具有优越和可定制机械性能的散装工程材料的微结构，从而提高燃气涡轮发动机应用部件的安全性、性能和能源效率。更一般地说，基础科学将使：(a)识别能够提高疲劳寿命的微结构类型，(b)了解这些不同晶界的强化机制，以及(c)实现这些结构的工艺图。上述每一项都将使微结构设计在广泛的材料和部件中表现出优异的机械性能。本研究的广泛影响有四个方面：(i)为高中科学教师提供材料营地，（ii）包括妇女和代表性不足的群体，（iii）通过HUB技术开放和广泛传播，以及（iv）包括技术转让在内的产业互动。

This research is about design of microstructures in superalloy structures that exhibit superior mechanical properties through grain boundary engineering. The approach of this research will be to develop and link process models, capable of producing microstructures with distinct grain boundary characteristics, with behavior models, capable of determining the fatigue life based on the microstructure. Through physics-based approaches, a process map will relate the hot deformation parameters for Nickel-based superalloys to the formation of distinct grain boundaries and microstructures. Microstructures that produce superior properties will be identified through inverse fatigue modeling and fabricated in bulk components. The validation of desired mechanical properties and mechanisms for achieving strengthening at distinct boundaries will be identified through novel in situ loading experiments coupled with strain field measurements and orientation mapping. If successful, the benefits of this research will include the design of microstructures in bulk engineering materials that exhibit superior and tailorable mechanical properties, thus producing an increase in safety, performance, and energy efficiency of components for gas turbine engine applications. More generally, the fundamental science will enable: (a) an identification of the types of microstructures that produce advances in fatigue life, (b) an understanding of the strengthening mechanisms of these distinct grain boundaries, and (c) process maps to achieve such structures. Each of the aforementioned items will enable designs of microstructures in a wide class of materials and components that exhibit superior mechanical behavior. The broader impact of this research is four-fold: (i.) a materials camp for high school science teachers, (ii.) inclusion of women and underrepresented groups, (iii.) open and wide-spread dissemination through HUB technology, and (iv.) industrial interaction including technology transfer.