Collaborative Research: GOALI: Laser Additive Manufacturing of Aerospace Components

该项目的目标是促进对激光添加剂制造工艺的基本了解，这对于LAM在广泛的航空航天应用中的工业实施是必要的。LAM结合了传统激光焊接的特点和自动生成复杂几何图形的能力。LAM的目标之一是降低制造具有复杂功能的新航空零部件的成本。在传统的制造方法中，复杂的特征必须被纳入铸造或锻造过程中，而且成本很高。通过使用LAM将复杂的功能添加到易于生产的通用制造组件中，可以实现成本节约。LAM的其他应用包括通过选择性添加材料来修复磨损或破裂的部件，这比更换部件要经济得多。在该项目中，将研究沉积过程变量与对航空航天应用至关重要的三个关键沉积特征之间的关系：熔池大小、残余应力和微观结构。这一理解将通过以工艺图的形式呈现的模型结果来证明，工艺图“描绘出”沉积特性与工艺变量的关系，如激光功率和激光速度。流程图将直接用于致力于推进LAM工艺的行业研究人员。这项研究建立了一个强大的合作团队，包括来自三所大学的学术研究人员，来自两个国家实验室的政府研究人员，以及几个行业合作伙伴。这项工作的结果预计将对LAM工艺的广泛工业实施产生重大影响。该项目还将让研究生、本科生和高中生学习将航空航天应用和制造约束与固体力学、传热学和材料科学的基础相结合的研究。

The objective of this project is to advance the fundamental understanding of the Laser Additive Manufacturing processes that is necessary for the industrial implementation of LAM in a wide range of aerospace applications. LAM combines characteristics of conventional laser welding with the ability to automatically produce complex geometries. One goal of LAM is to reduce the cost of manufacturing new aerospace components with complex features. In conventional manufacturing methods, complex features must be incorporated into a casting or forging process, at substantial cost. Cost savings can be realized by using LAM to add complex features to easy-to-produce, generic manufactured components. Other applications of LAM include the repair of worn or cracked components by selective material addition, which is substantially more economical than part replacement. In this project, the relationship between deposition process variables and the three key deposit characteristics critical to aerospace applications: melt pool size, residual stress and microstructure will be developed. This understanding will be demonstrated through model results presented in the form of process maps, which "map out" the dependence of deposit characteristics on process variables such as laser power and laser velocity. Process maps will be of direct use to industry researchers working to advance LAM processes. This research establishes a strong collaborative team including academic researchers from three universities, government researchers from two national labs, and several industry partners. The results of this work are expected to have a significant impact on the widespread industrial implementation of LAM processes. This project will also expose graduate, undergraduate and high school students to research integrating aerospace applications and manufacturing constraints with the fundamentals of solid mechanics, heat transfer and materials science.