Study on Laser Transmittance in Coaxial Laser Cladding

Abstract

The research of mechanism of laser passing through powder stream in coaxial laser cladding is of great significance for optimization of laser cladding process parameters and detective controls in the manufacturing process. The paper is focused in theoretical model of concentration field for powder stream from coaxial nozzle. Based on the model, the distributions of concentration of powder stream along central axis are simulated, geometric parameters of the nozzle are optimized. Theoretical model of laser passing through powder stream in coaxial laser cladding has been presented from Beer-Lambert law. The influence of powder flow rate on the laser transmittance has been discussed in view of the model. The system used for testing the power of the laser that has passed through powder stream in coaxial laser cladding is developed. It is shown that the geometric shape is fine while the width of the powder outlet is 0.4 mm and the angle of the outer powder cavity is 18°. It can be found that laser powder attenuation by powder stream tends to increase with increasing powder flow rate when the structure parameters of the nozzle are fixed. The results of the experiment shows that the deviation between theoretical values is consistent with experimental values while the laser power is 200 W, 300 W, 400 W and powder flow is choose in the range of from 0 to 50 mg/s.