Abstract Electron Beam Melting (EBM) is an additive manufacturing technique increasingly used by many industrial sectors, including the medical and aerospace industries. The application of this technology is, however, challenged by the lack of process monitoring and control systems to monitor process repeatability and component quality reproducibility. Various monitoring systems, mainly involving thermal and optical cameras, have been employed in previous attempts to study the quality of the EBM process. However, these systems have limitations, which include: (1) images generated unavoidably include monitoring-irrelevant regions beyond the processing area and (2) images are subject to keystone distortion. In this paper, a digital electronic imaging system prototype is described for the Arcam A1 EBM machine. This paper aims to: (1) disseminate the prototype design, (2) demonstrate the prototype ability to overcome limitations of the existing thermal and optical imaging systems, (3) showcase the potential for the prototype to serve as an alternative EBM monitoring technique, and (4) serve as a pilot study for future in-process EBM monitoring research with electronic imaging. Digital electronic images were generated by detecting both secondary electrons and backscattered electrons originating from interactions between the machine electron beam and the processing area using specially designed hardware. Prototype capability experiments at room temperature and approximately 320 ° C were conducted with digital images being generated and analysed from a Ti-6-Al-4V (as demonstrator material) test build. Results suggest that this prototype has significant potential to be used for in-process monitoring of EBM in many manufacturing sectors.

中文翻译：

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电子束熔化中反馈电子图像生成的初步研究及其在过程监控中的潜力

摘要 电子束熔化 (EBM) 是一种增材制造技术，越来越多地被许多工业部门使用，包括医疗和航空航天工业。然而，由于缺乏过程监控系统来监控过程重复性和组件质量再现性，该技术的应用受到了挑战。以前尝试研究 EBM 过程的质量时，已经采用了各种监控系统，主要涉及热像仪和光学相机。然而，这些系统具有局限性，其中包括：(1) 生成的图像不可避免地包含处理区域之外的与监控无关的区域，以及 (2) 图像会受到梯形失真的影响。在本文中，描述了 Arcam A1 EBM 机器的数字电子成像系统原型。本文旨在：(1) 传播原型设计，(2) 展示原型克服现有热成像和光学成像系统局限性的能力，(3) 展示原型作为替代 EBM 监测技术的潜力，以及 (4)作为未来电子成像过程中 EBM 监测研究的试点研究。数字电子图像是通过使用专门设计的硬件检测源自机器电子束和处理区域之间相互作用的二次电子和背向散射电子而生成的。在室温和大约 320°C 下进行原型能力实验，使用 Ti-6-Al-4V（作为演示材料）测试构建生成和分析的数字图像。