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

该合作研究资助机会学术联络与工业（GOALI）奖的研究目标是通过与工艺开发相关的广泛建模来推进对电子束制造的基本理解。该方法涉及三个关键的存款功能：熔池尺寸，残余应力和微观结构的模拟为基础的工艺图的发展。过程图将使用热力学数值模型，由力学和材料洞察指导，以管理无量纲热和机械过程变量。大量的电子束过程的数值模拟的结果将作为准无量纲图（工艺图）有效的沉积一个单一的合金在整个实际范围内的工艺变量。这些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，例如射束功率、射束速度、部件预热温度和部件尺寸。此外，这种方法将被用来考虑独特的电子束制造工艺方案，如使用快速移动的电子束在熔池内的熔池形状的剪裁，如果成功的话，这项研究的结果将提供一个基本的了解如何电子束工艺变量与最终的零件质量。这将提供一个非常需要的基础，比较电子束和竞争的激光为基础的过程中的制造和维修范围广泛的实际组件的相对强度。从事该项目的学生将在制造，固体力学，传热和材料方面获得多学科背景，这将使他们在工业和学术界都具有很高的价值。最后，项目活动将与两个学术机构正在进行的NSF支持的工程教育计划相结合。

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.