Interaction between laser beam and powder stream in the process of laser cladding with powder feeding

摘要

Based on Lambert-Beer theorem and Mie's theory, the attenuation of laser power by a powder stream was calculated and the laser intensity distribution at the laser spot on the surface of a workpiece was obtained. Simultaneously, the temperature distribution of the powder particles arriving at different sites on the surface of the workpiece was computed following the heat equilibrium principle. The computed results revealed that for a given stream spread and speed of powder particles, the intensity distribution of the laser spot and the temperature distribution of the powder particles reaching the surface of the workpiece are both greatly affected by the powder feeding rate and the feeding angle. It is suggested that the presented results should be considered in the laser cladding process in order to control the dynamic processes in a laser molten pool.