Challenges of Remanufacturing Using Powder Bed Fusion Based Additive Manufacturing

Remanufacturing is an industrial process of turning used products into products with the same quality as new ones. Of the processes comprising remanufacturing, the repair process poses the greatest challenge. Additive manufacturing (AM) is expected to bring innovation to the repair process of remanufacturing. Although, so far, the directed energy deposition (DED) type AM has been most frequently applied to remanufacturing and only a few studies applied powder bed fusion (PBF) type AM to remanufacturing, PBF demonstrates great potential for application in remanufacturing. This study aims to assess the feasibility of the application of PBF to remanufacturing. We conducted an experimental PBF-based repair and attempted to identify its challenges. In the experiment, 1) we used AlSi10Mg powder, 2) we first fabricated a 5 mm square cube sample by using PBF, 3) we next removed 0.4 mm of thickness from the sample with milling, 4) then we restored 0.44 mm of thickness using PBF, and 5) we observed the restored sample. The observation showed that: 1) misalignment in the restoration occurred, 2) keyhole defects and gas pores were found more in the boundary area between the original and restored parts, and 3) the microstructures showed polycrystals in the restored part. These factors impaired the quality and reliability of PBF-based repair and present challenges of enhancing the feasibility of applying PBF-based repair to remanufacturing. This study also examined the whole process of PBF-based remanufacturing, which includes not only the repair process but also the processes of component inspection, process design, pre-repair process, and post-repair process, and discussed the challenges in these processes. The challenges include the development of repair process design methods, supportless fabrication processes, and non-destructive test (NDT) techniques.