A comprehensive review of residual stress in metal additive manufacturing: detection techniques, numerical simulation, and mitigation strategies

As an emerging manufacturing process, metal additive manufacturing (AM) technology has revolutionized traditional design practices and enabled innovation in the materials engineering field, including the possibility of producing metal parts with complex geometries, increasing design freedom, and significantly lowering production costs. However, the thermal history process of cyclic heating and cooling creates residual stresses within the material, which may lead to deformation of the material, affecting the dimensional accuracy and mechanical properties of the parts forming. Thus, a comprehensive understanding of the metal AM underlying mechanism can provide insight into acquiring high-performance products. In this review, we first briefly introduce several common types of metal AM techniques and elucidate the mechanisms, leading to residual stress (RS) development. Subsequently, a summary of recent developments in common and online detection methods for monitoring RS is provided. Moreover, the thermodynamic coupling modeling approach for RS prediction is presented, along with several strategies aimed at enhancing the efficiency of simulation calculations. These details can help scholars identify suitable techniques. This paper also outlines some approaches for managing residual stresses, particularly emphasizing the effectiveness of energy field-assisted methods in metal AM processes in reducing RS and improving mechanical properties. Finally, the outlook is summarized to provide concrete directions for future research works.