Research on Cladding Process of Metal Powder during Laser Additive Manufacturing

The process of laser additive manufacturing consists of depositing successive layers of molten metal powder to create a near-net shape. A high-power laser is used to melt incoming metal powder, which forms a molten pool on the surface. As the latter moves beneath the laser, this newly created molten pool solidifies. By properly controlling the trajectory of deposition tracks, one can create a diverse range of shapes with varying complexities. In nature, the laser additive manufacturing technology is a continuous multilayer laser cladding process under the control of computer. The microstructure morphology of cladding layer is essential for the performance of as-deposited metal parts, so the cladding process was studied through related experiment. Based on the solidification theory, the microstructure morphology and the evolution rule were comprehensively analyzed. The results indicate that the temperature gradient and the solidification rate are the primary factor determining the microstructure morphology of cladding layer.