Fabrication of Single Crystals in Laser Powder Bed Fusion Using a Flat-Top Laser T. Kitashima 1, 2 and M. Watanabe1 Research Center for Structural Materials, National Institute for Materials Science (NIMS) 2 Department of Materials, Kyushu University The fabrication of single crystals of Ni-base superalloys using powder bed fusion has gained attention for high-temperature applications. We successfully fabricated a pure-Ni single crystal using a flat-top laser beam in the laser powder bed fusion process. In this study, we investigated the formation mechanism of the single-crystal structure in LPBF. The bidirectional laser scanning promoted the growth of <001>-oriented solidification cells in the build direction, resulting in a uniform <001>-texture formation. Simultaneously, a <001>-epitaxial growth occurred in a direction deviated by 45° to the scan direction (SD) near the melt pool tail. The 90° rotation of hatching direction (HD) at every layer caused the formation of the <101> textures parallel to both SD and HD. Thus, a single-crystal structure was formed via both the bidirectional laser scanning and the 90° hatching rotation. Materials Integration for Laser Powder Bed Fusion Process 1, Tomonori Kitashima1, Masahiro KusanoM. WatanabeNomoto1, Dmitry S. Bulgarevich1 and Jun Katagiri1 1 Research Center for Structural Materials, National Institute for Materials Science (NIMS) Laser Powder Bed Fusion (LPBF) is a process that directly builds three-dimensional structures by layering materials according to computer-aided design by utilizing laser beam. It enables the production of components with complex shapes that are difficult to produce using conventional technologies, as well as reducing the number of parts by manufacturing them as a single component. It is expected to be used increasingly in the aerospace and energy industries, where high quality products are required in small quantities. When applying this process to the production of high-performance heat resistant alloy components, it is important to control the occurrence of defects during the process, optimize the microstructure and mechanical properties, and develop new alloys suitable for AM. In our research, we have developed various multi-physics simulation and data science techniques (called as materials integration) for the LPBF process and developed in-situ monitoring techniques to validate these predictions and to inspect metal components fabricated by LPBF. A comprehensive overview of these achievements will be presented. 1 1, Houichi Kitano1, Kiata Ito1, Sukeharu Poster Presentation ｜NIMS Award Symposium 2023 P1 ｜ ProcessPP11--1133 PP11--1144 41
元のページ ../index.html#41