Wire arc additive manufacturing (WAAM) offers several advantages over other metallic additive manufacturing techniques, including lower equipment costs and greater flexibility in material composition. On the other hand, issues such as humping, oxidation and pore development can result from problems such as uneven welding, inconsistent feed rates and incorrect stand-off distance. So, the purpose of this study is to minimize these defects by optimizing the influential WAAM process parameters.
The aim of this study is to decrease pore size and improve the impact strength and nano-hardness of WAAM Al5356 walls by optimizing the stand-off distance in conjunction with welding speed and feed rates. An ANOVA coupled with GRA was used to predict the ideal settings. The optimal values were confirmed by nano-hardness mapping, and fractographic research shed light on the formation of cracks connected to pores.
Confirmation experiments revealed that the pore size was reduced to 83 ± 2 µm, which improved the impact strength by 67% and the nano-hardness by 70.9% while adopting the minimum welding speed of 60 cm/min and feed speed of 4 m/min with optimal stand-off distance of 15 mm. Excessive (20 mm) or insufficient (5 mm) stand-off distance caused issues with material deposition, leading to either excess buildup or insufficient coverage.
Streamlining the WAAM process is essential to improving material quality, reducing defects, boosting productivity and cutting costs. The results highlight how important stand-off distance is in minimizing pore formation, and the parametric investigation pinpoints the ideal circumstances. These tuned parameters show promise for high-performance, high-quality components that satisfy demanding industry requirements.
