From construction for construction: Additive manufacturing with gas-atomized recycled steel scrap

Climate change and energy scarcity, as well as changing socio-demographic structures and new user needs, drive major changes in the design, construction, and operation of buildings towards sustainability. As the building sector accounts for 35% of global energy consumption and 38% of global CO₂ emissions, the energy-efficient and sustainable design and maintenance of buildings will be an effective lever for creating sustainable living conditions in the future. The use of recycled materials in construction can reduce CO₂ emissions and ensure a circu`lar economy. In this work, a proof of concept is presented for additive manufacturing by laser powder bed fusion (PBF-LB/M) of metal powder obtained by gas atomization of recycled steel from demolished buildings. From the atomization of approximately 50 kg of steel scrap, 27.8 kg of particles finer than 90 μm were obtained, whereas particles ranging between 90 μm and 315 μm accounted for 14.1 kg. The samples made from the recycled powder had a relative density of 99.9%, no porosity and excellent mechanical properties. The average tensile strength of the produced material was 808 MPa, whereas the average yield strength was 716.4 MPa. These results demonstrate the feasibility and efficiency of using gas atomized recycled steel scrap for additive manufacturing, providing high-quality materials with excellent mechanical properties suitable for construction applications.