A Review on Wire Arc Additive Manufacturing of Magnesium Alloys: Wire Preparation, Defects and Properties

Wire arc additive manufacturing (WAAM) is widely used in the rapid prototyping of large parts because of its high deposition rate, high material utilization rate as well as low cost. However, the manufacturing process of magnesium alloy wires is relatively difficult, and the defects and performance of parts are difficult to control. This paper reviews the preparation process of magnesium alloy wires, which aims to achieve surface control and performance optimization of wires. Due to the quality of wires and the high processing temperature, the defects often occur in the deposition process. The common defects of magnesium alloy parts by WAAM are discussed and solutions are given to minimize it. The research advances in microstructure, mechanical properties, damping properties and corrosion properties are summarized. WAAM has performance advantages compared to casting, but the microstructure is inhomogeneous and the properties are anisotropic. Several quality improvement strategies are reported to improve properties and reduce defects. The effectiveness and applicability of these strategies are discussed, and the future prospects of WAAM for magnesium alloys are proposed. The preparation of high-performance wires, the formation mechanism of defects and microstructure are three keys for future improvement of WAAM for magnesium alloy.