Geometrical imperfections of AA5356-SiCp Composite Wall on AA7108 substrate using Wire Arc Additive manufacturing (WAAM)

The insertion of ceramic particulates into aluminum wire arc additive manufacturing (WAAM) is a challenging process due to particle feeding complexity, non-uniform distribution, and porosity formation. In this study, an alcohol-spray interlayer feeding technique was developed to introduce SiC particles into Al5356 walls deposited on AA7081 substrates. SiC powder was premixed with ethanol to create a low-viscosity suspension, which was sprayed between each two successive layers during WAAM deposition, enabling passive particle entrapment into the molten pool without modifying the torch or wire feeding system. Two thin-wall structures were fabricated , a reference wall deposited using pure Al5356, and a composite wall produced with SiC interlayer spraying. Microscopic characterization revealed clear differences in porosity evolution and reinforcement incorporation. The SiC reinforced wall exhibited a heterogeneous distribution of particles along the layer boundaries, governed by melt pool convection, alcohol evaporation, and wetting behavior between SiC and molten aluminum. Local agglomeration zones were observed where particle entrapment was insufficient .These findings confirm that alcohol-spray interlayer feeding is a feasible low-cost approach for introducing ceramic reinforcements into WAAM, while also highlighting its limitations regarding porosity control and particle distribution.