Modeling of laser power attenuation by powder particles for laser solid forming

Abstract Laser solid forming (LSF) is a typical laser additive manufacturing technology integrating rapid prototyping manufacturing and laser cladding. Laser power attenuation greatly influences the amount and distribution of laser energy. It is important to establish a theoretical model of laser power attenuation to effectively control the laser energy transmission and to ensure the stability of the molten pool. Considering the effects of overlap phenomenon among powder particles, a theoretical model of laser power attenuation is proposed by introducing the concept of the effective number of powder particles. The proposed model enables the accurate calculation of the laser power attenuation in arbitrary volume fraction of powder particles. The results indicate that the laser power attenuation is proportional to the powder feeding rate, and the increase rate of laser power attenuation is inverse proportional to the powder feeding rate. In addition, a simple method for measuring the laser power attenuation is also proposed to experimentally validate the proposed theoretical model. The experimental results validate the proposed method.