A multi-angle numerical model for laser cladding from the nozzle to cladding formation

Abstract

This study developed a comprehensive model that integrated fluid finite element computational mechanics, powder discrete element dynamics, and molten pool heat and mass transfer. The model accurately described the various phenomena occurring during the laser cladding process. This model, known as the multi-angle powder–gas–laser–liquid multiphase coupling model, extensively elucidated powder–gas transport, laser energy distribution, and heat and mass transfer within the molten pool. Additionally, the model comprehensively simulated the entire process of powder flow, from the nozzle to the formation of the cladding, even under varying substrate inclinations at different angles. Additionally, the study investigated the influence of substrate deflection angles, laser power, and scanning speed on the morphology of the cladding layer. The results revealed that as the substrate deflection angle varied from 0° to 150°, the height of the cladding layer first decreased and then increased, reaching a minimum value of 0.34 mm at 90°. Similarly, at a deflection angle of 90°, the width and offset of the layer first increased and then decreased, reaching peak values at 2.96 mm and 116 μm, respectively. However, the depth of the cladding layer displayed minimal variations, with an initial decrease followed by an increase. Moreover, as the laser power increased from 900 to 1500 W, the height, width, depth, and offset of the cladding layer gradually increased. Conversely, as the scanning speed increased from 5 to 11 mm/s, the dimensions of the layer gradually decreased. These findings address current challenges in numerical simulations, such as discontinuity and staging issues. Moreover, the findings provide valuable theoretical guidance for selecting and optimizing process parameters in multi-angle laser cladding, thereby filling a crucial knowledge gap.