Additive manufacturing of steel components by cold spraying

Design of steel structures in the construction industry uses built‐up or rolled steel sections. These are processed as steel elements and connected together at joints. Massive and complex steel nodes such as those in steel frame bridges or truss structures are still manufactured by forging or casting to avoid weld seams in highly stressed areas. Since this is a manual manufacturing process, it results in increased costs and time. Cold spray (CS) technology has recently attracted attention in aerospace and automotive engineering for producing metallic, composite coatings as well as repairing the surface damage of components in service. Additive manufacturing by cold spraying can offer significant advantages with respect to other additive manufacturing methods due to higher material deposition rates (up to 14 kg/h), lower energy consumption, and deposition in solid state. So far cold spraying has not been used for 3D‐printing of typical steel constructions.

In the preliminary test campaign, structural steel‐powder was investigated to evaluate their suitability for cold spraying in civil engineering applications. Simple flat specimens were used, and a range of metallographic and mechanical tests were conducted to determine the properties of the deposited coupons, such as the coating quality, layer thickness, the degree of porosity, micro‐hardness, and micro flat tensile test. This paper presents the results of the powder characterisation and the preliminary tests on the printed specimens.