Research group 3DInnovation, Stellenbosch University, Stellenbosch, South Africa.
Department of Mechanical Engineering, Nelson Mandela University, Port Elizabeth, South Africa.
J Microsc. 2022 Mar;285(3):121-130. doi: 10.1111/jmi.12930. Epub 2020 Jun 21.
X-ray computed tomography is a powerful tool to nondestructively inspect additively manufactured parts. Additive manufacturing of metals, especially laser powder bed fusion, is increasingly being adopted for serial production of critical components in aerospace, automotive and various other industries. The technology holds huge potential for more efficient material usage and light weighting of components, among the many advantages. As this new production method is being ramped up and refined in various industry sectors, X-ray tomography is critical to the advancement of the quality of the produced components. X-ray tomography allows the nondestructive evaluation of the structural integrity of the parts produced, which in turn provides confidence in the expected performance of the parts. Besides final inspection of parts for porosity/defects and dimensional tolerances for a pass/fail decision, X-ray tomography also has a critical role to play in advancing and improving the additive manufacturing processes. This process improvement refers to the inspection of small representative coupon samples on a microscopic scale, in order to optimize the process parameters such as laser power, speed, scan strategy and various others. In this work, we describe the evaluation of small solid cube coupon samples and lattice structure coupon samples. These examples are meant to improve the understanding of the potential of X-ray tomography in advancing additive manufacturing processes (in contrast to its usual use for nondestructive testing of final parts), thereby providing support towards qualification of these processes and the parts produced in these processes. X-ray tomography, therefore, plays a key role in the adoption and qualification of high-quality metal additive manufacturing.
X 射线计算机断层扫描是一种用于无损检测增材制造零件的强大工具。金属的增材制造，特别是激光粉末床熔合，越来越多地被用于航空航天、汽车和各种其他行业的关键部件的批量生产。这项技术具有提高材料利用率和减轻部件重量等诸多优势，具有巨大的潜力。随着这项新的生产方法在各个行业中得到提升和完善，X 射线断层扫描对于提高所生产部件的质量至关重要。X 射线断层扫描允许对生产部件的结构完整性进行无损评估，从而为部件的预期性能提供信心。除了对零件进行最终的孔隙率/缺陷和尺寸公差检查以做出合格/不合格的决定外，X 射线断层扫描在推进和改进增材制造工艺方面也起着至关重要的作用。这种工艺改进是指在微观尺度上对小代表性的试片进行检查，以便优化工艺参数，如激光功率、速度、扫描策略等。在这项工作中，我们描述了对小实心方块试片和晶格结构试片的评估。这些例子旨在提高对 X 射线断层扫描在推进增材制造工艺（与通常用于最终零件无损检测的用途相反）方面的潜力的理解，从而为这些工艺和在这些工艺中生产的零件的资格认证提供支持。因此，X 射线断层扫描在采用和验证高质量金属增材制造方面发挥着关键作用。
