Influence of scanning pattern on the edge collapse of solid parts in laser metal direct forming

Edge collapse is one of the critical problems which seriously affect the forming accuracy of solid parts in laser metal direct forming (LMDF). This study was focused on the influencing rule of scanning pattern on the edge collapse of solid parts. The relationship between the inclination angle of motel pool on the edge of solid part and the scanning pattern was analyzed and the change rule of the inclination angle with the increase of cladding layers was also analyzed in detail. The force condition of motel pool at the edge of solid part was calculated. The results showed that the scanning pattern seriously affected the inclination angle of motel pool because of mutual interference of adjacent tracks. Different scanning patterns made the inclination angle of motel pool show significant difference with the increase of cladding layers. Molten pool began to flow leading to edge collapse when the inclination angle of motel pool was about 25°-32°. Crown Copyright;