Influence of interlayer nitrogen cooling on microstructure and mechanical properties of 5356 Al–Mg alloy walls produced by WAAM

Abstract Nowadays, wire arc additive manufacturing can contribute to achieving zero overproduction by enabling on-demand fabrication of metal spare parts and reducing the need for excess inventory. However, using WAAM to manufacture metal components with aluminum alloys encounters challenges due to heat accumulation in the subsequent layers, which negatively impacts the structural integrity of the final part. This study investigates a new approach called interlayer nitrogen cooling (INC) that uses nitrogen gas as a cooling medium between subsequent layers to mitigate the heat accumulation induced by different thermal cycles, resulting in better structural integrity of the final part. The study investigated a comparison between the natural cooling (NC) approach and the INC approach; the results showed that INC approach resulted in grain size refinement by about 82%, which enhanced the mechanical properties. The tensile strength increased by 26% for the INC processed walls compared to the NC. This paper will discuss the details of the cooling system, microstructure analysis, porosity formation of Al–Mg alloy and its tensile properties.