Review on scanning pattern evaluation in laser-based additive manufacturing

Laser-based additive manufacturing (LBAM) is a group of advanced manufacturing processes used to produce metal components and functionally graded products. Production in LBAM is either limited to the formation of thin or thick coatings on a substrate by laser metal deposition or the production of a fully functional metallic product by selective laser melting. In every case, LBAM fabricated components require optimization for the process parameters to avoid defects, such as porosity, crack holes, thermal deformation, and mechanical strength. As a key link in the laser additive manufacturing (LAM) process, laser scanning path planning is an effective strategy for balancing the temperature field of the formed part, avoiding stress concentration, and preventing deformation and cracking. Efficient, accurate, and reasonable planning of the laser scanning path is of great significance for improving the processing efficiency of the process data, prolonging the life of the laser scanning system, and improving the forming quality of the specimen. Through many studies, it was found that the scanning pattern of the lasers has a significant impact on the mechanical properties and deformations caused by a thermal mismatch during the process. Therefore, it is essential to have in-depth knowledge about path planning in LBAM. Our review mainly focuses on the influence of scanning patterns on deformation, temperature, and mechanical properties in LBAM. Finally, our paper discusses the current study limitations and some future studies in LAM technology.