Regional planning of laser scanning path based on overhang structure recognition

Planning of laser scanning path is the key process strategy of selective laser melting (SLM) additive manufacturing technology. Combining the significant structural characteristics of a three- dimensional model to realize process path planning is an important measure to improve the forming quality of parts. An SLM regional path planning method based on suspension recognition was proposed. By identifying the suspension characteristic region of the three-dimensional model, combined with the contour offset algorithm, the forming region segmentation and scanning path planning are realized. The effects of scanning line angle, interlayer rotation and different offset distance on the forming quality of suspension structure characteristics were studied by means of numerical simulation and process test. The results show that when the overhanging edge is offset by a reasonable distances and the scanning strategy parallel to the overhanging edge is adopted in this area, the deformation and residual stress on the overhanging edge can be reduced by 54% and 73% at most.