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

本研究旨在通过晶界工程来设计具有优异力学性能的高温合金组织。这项研究的方法将是开发能够产生具有明显晶界特征的微观组织的工艺模型，并将其与能够基于微观组织确定疲劳寿命的行为模型相联系。通过基于物理的方法，工艺图将镍基高温合金的热变形参数与明显的晶界和组织的形成联系起来。将通过反向疲劳建模来识别产生优异性能的微观组织，并将其制造成大块部件。通过新的现场加载实验，结合应变场测量和取向图，验证所需的机械性能和在不同边界实现强化的机制。如果成功，这项研究的好处将包括设计出具有优异和可定制的机械性能的散装工程材料的微结构，从而提高燃气轮机发动机应用部件的安全性、性能和能效。更广泛地说，基础科学将使：(A)确定能够提高疲劳寿命的微结构的类型，(B)了解这些不同晶界的强化机制，以及(C)实现这种结构的工艺图。上述每一项都将使设计出具有优异机械性能的各种材料和部件的微结构成为可能。这项研究的更广泛影响有四个方面：(I)高中科学教师材料夏令营，(二)将妇女和代表性不足的群体包括在内(三)通过枢纽技术进行公开和广泛的传播，以及(四)产业互动，包括技术转让。

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.