Harnessing manufacturing elements to select local process parameters for metal additive manufacturing: A case study on a superconducting solenoid coil

Bernhard Auchmann,Julian Ferchow,André Brem,Manuel Biedermann,Mirko Meboldt,Pascal Müller

doi:10.1016/j.addma.2021.102140

Bernhard Auchmann, Julian Ferchow + Show 4 more

Open Access

https://doi.org/10.1016/j.addma.2021.102140

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Abstract

In additive manufacturing (AM), low geometrical tolerances, high-quality material properties, and low surface roughness are challenges. To increase the process capabilities, a promising concept is to tailor process parameters for the fabrication of a part. Instead of selecting identical process parameters to the geometry of the whole part, different sets of process parameters are assigned to different regions named manufacturing elements (MEs). The ME approach offers three main advantages: significant reduction of required sacrificial support structures based on the reduced build angles and less post-processing efforts; reduced AM processing time due to less sacrificial support structures and a higher laser speed; and local adjustment of the material and surface properties. Previous studies have examined the ME approach and applied it to simplified test samples. This study shows an end-to-end implementation of the ME approach for the fabrication of a real-world industrial part and highlights the associated opportunities and challenges for the implementation. The application is demonstrated for a complex-shaped industrial part that can only be manufactured using the ME approach. The industrial part is a winding former of a superconducting solenoid coil. The implementation consists of three major steps: (1) the development of a process parameter model for laser-based powder bed fusion ( L -PBF) and stainless steel 316 L; (2) segmentation of the part into MEs; and (3) use of the enhanced design freedom for surface texturing. The ME approach facilitated support-free fabrication of the part with build angles of as low as 25°. The enhanced design freedom enabled surface texturing, which allowed the maximum shear strength to be improved by 63% compared to that of a nontextured surface. The results are discussed, and possible enhancements and research directions are outlined, such as the automated assignment of process parameter sets. The results are applicable to reduce the costs of a superconducting solenoid coil for the treatment of cancer with proton beams. This can enable a larger number of patients to have access to this cancer treatment. In addition, the results are further applicable to increase the performance of the future circular collider at CERN.

Highlights

Laser-based powder bed fusion (L-PBF) is a layer-based additive manufacturing (AM) process that enables the fabrication at reduced costs and short lead times of complex-shaped and customized metal parts, which may not be possible with conventional manufacturing processes [1]
Instead of selecting identical process parameters to the geometry of the whole part, different sets of process parameters are assigned to different regions named manufacturing elements (MEs)
Support structures are required during fabrication but must be removed from the produced part, which is a Abbreviations: AM, Additive manufacturing; CAD, Computer-aided design; canted cosine theta (CCT), Canted cosine theta; FCC, Future Circular Collider; fused deposition model (FDM), Fused deposition modeling; ME, Manufacturing elements

Summary

Introduction

Laser-based powder bed fusion (L-PBF) is a layer-based additive manufacturing (AM) process that enables the fabrication at reduced costs and short lead times of complex-shaped and customized metal parts, which may not be possible with conventional manufacturing processes [1]. Despite these advantages, industrial applications of L-PBF are still limited. It was developed for the Future Circular Collider (FCC) program of the European Organization for Nuclear Research (CERN) [10]

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