A review on wire arc additive manufacturing: Processing parameters, defects, quality improvement and recent advances

Arc welding-based additive manufacturing techniques are becoming promising for metal additive manufacturing due to their capability of economically producing large-sized components with relatively high deposition rates. This article introduces wire arc additive manufacturing (WAAM) and reviews the microstructure and mechanical properties of various metals and alloys fabricated through this technique. Research indicates positive results as the mechanical properties of WAAM fabricated materials, such as titanium and nickel-based alloys, are found relatively comparable to cast or wrought materials. A feasible state-of-the-art WAAM requires controlling several processing parameters to achieve sound components, so an elaborated review is presented on selecting suitable process parameters. High-quality production in WAAM is limited due to elevated levels of heat inputs, causing several materials processing challenges and defects. Common challenges faced in the fabrication of various metals and alloys through WAAM, including high residual stresses, porosity, delamination, and cracking, are described in this article. The defect mitigation techniques and the recent advances performed in the field of WAAM are summarized in the last section of this paper. This paper concludes that WAAM can be an alternative process for high-quality manufacturing and presents a future vision to make WAAM more industry-oriented technology.