A Review of Challenges for Wire and Arc Additive Manufacturing (WAAM)

Wire and arc additive manufacturing (WAAM) has a high deposition rate, high material utilization, and compact structure, so it is especially suitable for low-cost, high-efficiency, and fast near-net-shape manufacturing of large-scale complex parts. However, in the WAAM process, many challenges limiting the quality and performance of the deposited layers, such as the WAAM process options and material selections limiting deposition performance and microstructure, manufacturing defects weakening the quality of the deposited layer, and the difficulty in predicting the quality and the performance. This paper outlines the challenges of WAAM, summarizes the challenges of material selections and processing methods, improving microstructure and performance, defect monitoring and improvement, simulation technology and artificial intelligence technology introducing predictive WAAM, and finally analyzes its development trends.