Additive manufacturing with SLM technology provides weight savings, even for dynamically loaded metallic components on railway vehicles

Abstract. Lightweight construction is important in the design of railway rolling stock. Mild steels are often used for dynamically loaded damper brackets. This investigation was conducted to see if it is possible to redesign such a dynamic loaded damper bracket for additive manufacturing, especially for selective laser melting (SLM) technology, using a mild steel powder. A dynamic loaded part of a high-speed train was redesigned for SLM manufacturing technology. The design was created and topologically optimized with computer-aided design (CAD) tools. Validation of design and manufacturing (inner stress) was performed by simulation (Ansys) and by physical tests (tensile test, V-notch impact test, and fatigue test). Both the results of the simulation and of the physical tests are presented here. The design is approved by the design authority. A complete train of nine cars was equipped with 16 pieces of the redesigned part and was in validation phase. Considerable weight savings could be achieved. The mild steel powder that was used (short name E185) fulfilled the expectations according to strength and ductility. The described way of working for approval process can be understood as an example for redesign of other components. An Alstom standard for manufacturing and purchasing AM (additive manufactured) parts has been written.