Multi-Material Additive Manufacturing of S690/Fe-Mn-Si-Cr-Ni SMA Joints with 30% Enhanced Static and Fatigue Life for Structural Applications through L-DED

Alper Kanyilmaz

European Union (EU) is the world’s second-largest steel-producing region with an annual production of approx. 150 million tonnes.
Since steel fabrication is one of the major sources of waste and CO2 generation in EU, novel approaches are therefore required to address this issue. Multi-material structural steel components fabricated through resource efficient laser directed energy deposition (L-DED) process that can bypass the characteristic strength ductility trade-off of steel structural components and therefore have a minimum 30% enhanced fatigue life are proposed in this project. The resource-efficient process of L-DED will provide a way for steel components fabrication with waste reduction and seamless material combinations that are otherwise difficult to attain. The developed multi-material components will also have a minimum of 30% enhanced lifecycle thus reducing waste generation from industries with considerable steel structural components applications. Initially, a digital framework with more than 90% accuracy will be developed through the finite volume method and discrete element method to evaluate and adjust the L-DED process and bypass expensive experimental approaches. Afterward, L-DED process parameters and interface strengthening approaches will be optimized for defect-free and high-density (>99% relative density) component fabrication. Lastly, the 30% enhanced life cycle of the proposed S690/Fe-Mn-Si-Cr-Ni multi-material structural joints under static, dynamic, and extreme thermal conditions will be established through experiments. The outcomes of the proposed project will help in providing the foundation for creating multi-material components with extraordinary and controllable behavior, as well as providing the L-DED process as a viable route for the fabrication of such components.