多光束变光斑激光定向能量沉积工艺及分析模型

In order to give consideration to both forming efficiency and precision of laser directed energy deposition (LDED), a novel technique for LDED with variable spot sizes based on multiple beams is proposed. A multi-beam laser cladding head with variable spot sizes is developed. The cladding head is designed with three laser beams, which converge at the focal spot, and the diameter of each laser beam is different. A control module for changing the laser spot size is developed to realize the rapid conversion between small spot and large spot by controlling different combinations of laser beams. Based on the principles of energy conservation and mass conservation, an analytical model for LDED with variable spot sizes based on multiple beams is established by analysing the interaction between laser, powder and substrate. Experiments have confirmed that the analytical model could predict the size of the clad and the catchment efficiency of the powder under different process parameters, which can provide a reference for parameter optimization and parameter selection of the process. It has the advantages of fast response speed, high reliability, high utilization rate of laser energy, which provides a new method and the corresponding theoretical basis for LDED technology with variable spot sizes.