Research On Laser Cladding Deposition Of 316L Stainless Powder

Laser cladding deposition of metal part is one of the major trends of additive manufacturing technology. First of all, an experimental platform, which used for laser cladding multi-dimensional deposition of metal parts with large angle cantilever, was designed and manufactured. Meanwhile, the optimal process parameters of laser cladding deposition of 316 L powder were also studied and determined by using the experimental platform. The main contents are as follows.According to the need of laser cladding metal parts with large angle cantilever, the overall design was proposed and concrete structure was optimally designed. The experimental platform used for laser cladding multi-dimensional deposition was manufactured and the forming process was automated.Process test of 316 L powder was studied by using the method of orthogonal test. Process parameters were optimized by the orthogonal analysis. Process parameters of contour line are as follows: laser power is 300 W; scanning speed is 5 mm/s; feeding rate is 4 g/min. Process parameters of filling line are as follows: laser power is 450 W; scanning speed is 4 mm/s; feeding rate is 4 g/min. The cladding samples of 316 L powder by using optimal cladding process parameters form well. The microstructure presents metallurgical bonding state between two layers and does not have pores and cracks, so it meets manufacturing requirements.Metal part with large angle cantilever was formed by using the independently developed experimental platform. This preliminary verified the function of laser cladding multi-dimensional deposition and laid a foundation for the forming of complex parts. A cube sample whose size is 20 mm×20 mm×60 mm was formed by using Z-shaped scanning mode and contour offset mode. The results of mechanical properties test are as follows: the average yield strength is 246 MPa; the average tensile strength is 551 MPa; the average elongation is 16.3%. Microstructure observation shows that: Layer thickness is uniform and it presents metallurgical bonding state between two layers. Columnar crystal and isometric crystal vertically grow in the interface between two layers. The internal organization of the layer is composed of uniform isometric crystal. The organization does not have defects such as, pores and cracks.