Review of Aluminum Alloy Development for Wire Arc Additive Manufacturing

Abstract

Processing of aluminum alloys by wire arc additive manufacturing (WAAM) gained significant attention from industry and academia in the last decade. With the possibility to create large and relatively complex parts at low investment and operational expenses, WAAM is well-suited for implementation in a range of industries. The process nature involves fusion melting of a feedstock wire by an electric arc where metal droplets are strategically deposited in a layer-by-layer fashion to create the final shape. The inherent fusion and solidification characteristics in WAAM are governing several aspects of the final material, herein process-related defects such as porosity and cracking, microstructure, properties, and performance. Coupled to all mentioned aspects is the alloy composition, which at present is highly restricted for WAAM of aluminum but received considerable attention in later years. This review article describes common quality issues related to WAAM of aluminum, i.e., porosity, residual stresses, and cracking. Measures to combat these challenges are further outlined, with special attention to the alloy composition. The state-of-the-art of aluminum alloy selection and measures to further enhance the performance of aluminum WAAM materials are presented. Strategies for further development of new alloys are discussed, with attention on the importance of reducing crack susceptibility and grain refinement.

Wire Arc Additive Manufacturing (WAAM) for Aluminum-Lithium Alloys: A Review

“…Cracking is a high-temperature phenomenon that usually takes place in alloys in the liquid melt pool. When this defect occurs during WAAM in aluminum alloys, it is known as solidification cracking; it is not the common defect known as hot-cracking, which occurs in arc welding and takes place in the partial melted zone [ 76 ].…”

A Brief Review on The Common Defects in Wire Arc Additive Manufacturing

“…Thus, controlling the shrinkage of the welded material can prevent cracking during the solidification progress. Also, in WAAM process a clean, dry, and good wire surface quality a key to produce parts free of hydrogen and avoids hydrogen induced cracking [137]. Furthermore, the chemical composition of welded material can be improved by adding a sufficient filler wire, in arc welding processes to degrade SC [138].…”

Wire arc additive manufacturing of aluminium alloys for aerospace and automotive applications: A review

“… Flexibility in making complex parts [90]. The possibility to create high-quality parts, while maintaining the mechanical strength and at the same time benefiting from a lower weight of the components [87,91]. The increasing demands of aluminium parts, particularly alloy with high strength in the aerospace and automobile domain, can be actualised with the use of WAAM as a future economic opportunity [92].…”