A Review of the Mechanisms of Porosity Formation in Aluminum Alloy Parts Produced via Wire Arc Additive Manufacturing

Wire and Arc Additive Manufacturing (WAAM) is recognized as one of the most significant techniques in metal additive manufacturing (AM). In this process, a filler wire is melted by an electric arc, and metal droplets are deposited layer by layer along a predetermined path. Over the past decade, aluminum alloys fabricated through WAAM have gained considerable attention across industries such as aerospace, automotive, marine, and energy. This growing interest is attributed to advantages including high production efficiency, the ability to manufacture large components without dimensional constraints, low weight, corrosion resistance, and favorable mechanical properties. Nevertheless, despite these benefits, porosity remains a critical challenge in the WAAM of aluminum alloys. The presence of pores can result in stress concentration, cracking, and reductions in tensile strength and fatigue resistance factors that directly restrict the broader industrial adoption of this technology. The present study investigates the primary causes and mechanisms of porosity formation in aluminum alloys processed by WAAM. Specifically, attention is given to hydrogen-induced pores, gas-related porosity, shrinkage cavities, and porosity arising from the evaporation of low-boiling-point alloying elements.

کلیدواژه ها:

Wire arc additive manufacturing ، Aluminum alloys ، Cavity formation mechanism ، Porosity ، Hydrogen pores