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7177 |
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Wednesday, June 22, 2022, Saal Brüssel 2:20 PM Brazing of demanding materials and joints |
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An investigation into the brazing of additively manufactured 316L stainless steel |
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Frances Livera* / University of Sheffield, Great Britain Russell Goodall/ University of Sheffield, United Kingdom Iain Todd/ University of Sheffield, United Kingdom Martin Cuddy/ Culham Centre for Fusion Energy, United Kingdom |
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Additive manufacture (AM) and brazing are two areas that have seen a significant quantity of research individually, but their combination has not been widely investigated. Combining the geometrical freedom of AM with a joining process could reduce component lead-times and enable complex joint geometries. The disparity between the typical surface finish of AM (5-35 µm) and the surface roughness requirements for a brazed joint (0.6 - 1.6 µm) is the main challenge in combining the techniques. The freeform nature of AM means that the implementation of tailored surface topography could aid wettability of the braze alloy and enable strong joint formation. It may lead to the ability to create more complex joint geometries and reduce the effects of mismatched material properties, by controlling the braze alloy flow direction. Results will be presented on the manufacture and characterisation of 316L stainless steel joints using native AM surfaces. The surfaces are built in three build directions (horizontal, vertical and at 45 °) to determine the effects of different surface roughness values and examine the three most extreme AM build directions. A comparison will be made between brazing via vacuum furnace and furnace brazing in terms of the quality of the joint formed, and different braze alloy flow properties will be examined. Microstructural analysis presented will examine whether grain growth and orientation in the brazed joint is affected by the texture of an AM part and tomography will be used to examine the joint non-destructively. |