Shaped metal deposition technique in additive manufacturing: A review

Shaped metal deposition is a relatively new additive layered manufacturing method. It is a novel technique to build net-shaped or near-net-shaped metal components in a layer-by-layer manner via applying metal wire and selection of a heat source such as laser beam, electron beam, or electric arc. It is a manufacturing method used for production of complex featured and large-scaled parts, especially in aerospace and metal-die industries. This method can lower the cost of fabricated parts by reducing further machining and finishing processes and shortening lead time. This article presents a comprehensive literature review on shaped metal deposition, and it mainly aims to highlight some of the areas which were reported by the researchers in this field to give an extensive overview of shaped metal deposition processes, classification of its methods, and their applications. The presented literature review covers extensive details on microstructure, mechanical properties, and residual stresses induced in the metallic parts produced by various shaped metal deposition techniques as well as fabrication of dual-material parts. Additionally, grain refinement of the deposition morphologies using various techniques, especially the arc pulsation process, was mentioned. This study demonstrates that shaped metal deposition method using wire can be considered as a distinctive low-cost method for fabricating large-scaled components due to high deposition rates, high efficiencies, and dense part production capabilities. However, the accuracy and surface finish are less compared to laser and electron beam melting methods.