A project led by Tewer Engineering called High Thermal Inertia Solar Cavity Receiver (THICAV) has been initiated with the goal to refine their previous solar receiver and make it possible to retrofit to already existing industries. This cavity receiver is practically designed to directly heat different industries with the transfer fluid and not be converted to electricity. Therefore, it could replace natural gas and other non-renewable energy sources. This causes high demands on good adaptability and cost-effective solutions. Besides the design, important topics are related to material choice and type of manufacturing process. This thesis will analyze the suitability of manufacturing through Wire Arc Additive Manufacturing (WAAM) and which materials are adequate for the receiver.

Literature studies laid the foundation for this thesis which contributed to both material selection and determination of the initial welding parameters. A design of experiment was conducted to investigate the outcome of different welding parameters for the selected materials. The outcome of the different welding parameters was validated and verified through mechanical testing. Finally, a scaled down prototype of the most complex parts of the receiver was manufactured with the most suitable welding parameters.

With the given conditions, AISI 309 and Inconel 625 were chosen from the material selection and further investigated. However, there are other alloys in the same material groups which might expose a higher performance e.g., better thermal properties. The selected materials were considered most suitable due to previous knowledge related to WAAM of these alloys and material availability.

The material evaluation exposes that heat input has a very limited impact on the mechanical properties for both materials and it is difficult based on the acquired results to determine which welding parameters that are best. In terms of producibility higher interpass temperatures are beneficial as it speeds up production. Therefore, it can be determined that an interpass temperature of 200°C and 1000 mm/min torch travel speed are the most adequate parameters for the WAAM process for these two materials.

The aim of prototype manufacturing was to determine if the receiver was printable with the chosen material and the WAAM method. Even if the prototype was printed only in AISI 309 a similar behavior could be observed for welding of Inconel 625. It could therefore be established that receiver most likely is printable with both materials since the prototype contained the most complex parts of the receiver.