An increasing demand for flexibility and product integration, combined with reduced product development cycles, leads to continuous development of new manufacturing technologies such as additive manufacturing. Wire and arc additive manufacturing (WAAM) provides promising technology for the near net-shape production of large structures with complex geometry, using cost efficient production resources such as arc welding technology and wire materials. Compared to powder-based additive manufacturing processes, WAAM offers high deposition rates as well as enhanced material utilization. Because of the layer-by-layer built up approach, process conditions such as energy input, arc characteristics, and material composition result in a different processability during the additive manufacturing process. This experimental study aims to describe the effects of the welding process on buildup accuracy and material properties during wire arc additive manufacturing of aluminum structures. Following a process development using pulse cold metal transfer (CMT-P), linear wall samples were manufactured with variations of the filler metal. The samples were analyzed in terms of surface finishing, hardness, and residual stress. Furthermore, mechanical properties were determined in different building directions.

Additive manufacturing (AM) in industrial applications benefits from increasing interest due to its automation potential and its flexibility in manufacturing complex structures. The construction and architecture sector sees the potential of AM especially in the free form design of steel components, such as force flow optimized nodes or bionic-inspired spaceframes. Robot-guided wire and arc additive manufacturing (WAAM) is capable of combining a high degree of automation and geometric freedom with high process efficiency. The build-up strategy (layer by layer) and the corresponding heat input influence the mechanical properties of the WAAM products. This study investigates the WAAM process by welding a bar regarding the build-up geometry, surface topography, and material properties. For tensile testing, an advanced testing procedure is applied to determine the strain fields and mechanical properties of the bars on the component and material scale.

The use of carbon fibre-reinforced plastics (CFRP) is growing significantly in all areas of lightweight construction. Thermosets like epoxy still build a major part of deployed matrix material. A suitable joining technology for CFRP is adhesive bonding. However, the bonding performance is well reduced because of contaminations. To achieve full bond-strength, adhesion of the adhesive to the components is essential. One innovative method for surface pre-treatment is laser radiation. Former investigations show that an important parameter is the absorption. As a result of that, a UV laser (wavelength of 355 nm) and a CO₂ laser (wavelength of 10600 nm) were used to pre-treat specimens manufactured from 120°C curing epoxy. The focus is to achieve a selective removal of resin without impairing the fibres. Lap-shear specimens have been pre-treated, bonded with an one component epoxy film adhesive and tested. The laser pre-treated specimens achieve the same bond strength as references prepared by manual abrading. Furthermore, the mechanisms of interaction between laser radiation and matrix material as well as fibres are discussed considering the different heat deposit and absorption behaviour of the emitted radiations.