Research progress in laser additive manufacturing of aluminum alloys: Microstructure, defect, and properties

Laser additive manufacturing (LAM) has attracted significant interest in developing Al alloys due to its potential to fabricate structural components at low cost and high efficiency. Nevertheless, LAM Al alloys still suffer many issues, including heterogeneous microstructure, various defects, and poor mechanical properties, significantly hindering the advancement of LAM Al alloys. This article seeks to provide a comprehensive overview of the current advancements made in the field of LAM Al alloys and attempts to establish an in-depth relationship between microstructural characteristics, defects, and performances. Development status and limitations of LAM technologies are described, microstructural characteristics of Al alloys in LAM are introduced, mechanisms of formed defects and corresponding mitigation measures are discussed, and current quality improvement strategies are summarized. Following the research of previous work, this review will provide an outlook on overcoming the existing challenges and provide a helpful resource and reference for the development of LAM Al alloys.