Gas–solid two-phase flow in continuous coaxial laser cladding powder feeding process

Laser cladding is an advanced surface coating technology, particularly effective for small-scale production of high-value components. This study employed a three-dimensional computational fluid dynamics model to examine the effects of particle size distribution, carrier gas flow rate, and protective gas flow rate on the concentration and velocity distribution of metal particles during the laser cladding powder feeding process. The results revealed that, compared to particles with an average size ranging from 50 to 125 μm, the particle concentration at the focusing position increased as the average particle size decreased, and the average velocity of smaller particles was higher. Additionally, when varying the carrier gas flow rate between 6 and 12 l/min, it was observed that particle concentration at the focusing position increased as the carrier gas flow rate decreased, while the average particle velocity rose with an increase in the carrier gas flow rate. Similarly, when adjusting protective gas flow rates between 10 and 40 l/min, it was found that the particle concentration increased as the protective gas flow rate decreased, while the average particle velocity increased with a higher protective gas flow rate.