Additive manufacturing technology holds broad prospects in the production of complex metal components for the aerospace industry

owing to its high design flexibility

excellent dimensional accuracy

and streamlined manufacturing process. However

challenges such as limited spatial dimensions

high manufacturing costs

and process uncertainties during prolonged forming restrict the direct additive manufacturing of large-scale components. Modular design combined with segmented manufacturing and welding technology can effectively mitigate these issues

making it a current research focus in this field. This paper systematically elaborates on the unique microstructural characteristics of metal structures produced by additive manufacturing and the associated welding challenges. It summarizes strategies to address these difficulties from the perspectives of alloy composition optimization

welding method innovation

and the application of auxiliary technologies. The principles and process characteristics of commonly used welding methods for additively manufactured structures are introduced in detail

with a focus on the weldability of additively manufactured aluminum alloys

titanium alloys

iron-based alloys

and nickel-based alloys. Furthermore

the progress in engineering applications of welding for aerospace additive manufacturing components is reviewed. Finally

it looks forward to the potential application of artificial intelligence in the field of welding manufacturing.