GOALI/Collaborative Research: A Modeling Base for Process Development of Electron Beam Manufacturing

GOALI奖的研究目标是通过与工艺开发相关的广泛建模，促进对电子束制造的基本理解。该方法包括为熔池大小、残余应力和微观结构这三个关键沉积特征开发基于模拟的工艺图。在力学和材料的指导下，将使用热力学数值模型开发工艺图，深入了解控制无量纲热和机械工艺变量。大量电子束过程数值模拟的结果将以准无因次图(过程图)的形式呈现，在整个实际过程变量范围内对单一合金的沉积是有效的。这些曲线图将允许预测熔池尺寸、残余应力和微观结构作为工艺变量的函数，如束流功率、束流速度、部件预热温度和部件尺寸。此外，这种方法将被用于考虑电子束制造特有的工艺方案，例如利用电子束在熔池中的快速移动来裁剪熔池形状。如果成功，这项研究的结果将提供关于电子束工艺变量如何与最终零件质量相关的基本理解。这将为比较电子束和基于激光的竞争工艺在制造和修复各种实际部件方面的相对强度提供亟需的基础。从事这个项目的学生将在制造、固体力学、传热学和材料方面发展多学科背景，这将使他们在工业和学术界都具有极高的价值。最后，项目活动将与两所学术机构正在进行的由国家科学基金会支持的工程教育倡议相结合。

The research objective of this Collaborative Research Grant Opportunity for Academic Liaison with Industry (GOALI) award is to advance the fundamental understanding of electron beam manufacturing through broad-based modeling tied to process development. The approach involves the development of simulation-based process maps for three key deposit features: melt pool size, residual stress and microstructure. Process maps will be developed using thermomechanical numerical models guided by mechanics and materials insight into governing nondimensional thermal and mechanical process variables. Results from large numbers of numerical simulations of electron beam processes will be presented as quasi-nondimensional plots (process maps) valid for deposition of a single alloy over the full practical range of process variables. These plots will allow the prediction of melt pool size, residual stress and microstructure as a function of process variables such as beam power, beam velocity, part preheat temperature and part size. In addition, this approach will be used to consider processing scenarios unique to electron beam manufacturing, such as the tailoring of melt pool shape using rapid movement of the electron beam within the melt pool.If successful, the results of this research will provide a fundamental understanding of how electron beam process variables relate to final part quality. This will provide a much needed basis for comparing the relative strengths of electron beam and competing laser-based processes in the fabrication and repair of a wide range of practical components. Students working on this project will develop a multidisciplinary background in manufacturing, solid mechanics, heat transfer and materials that will make them highly valuable in both industry and academia. Finally, project activities will be integrated with ongoing NSF-supported engineering education initiatives at both academic institutions.