Analysis of powder flow from the nozzle to the substrate in multiangle laser cladding

This study, investigated the powder flow field for multiangle laser cladding, bridging theoretical gaps in the repair of metal parts with tilted and complex surface, specifically those are immovable and nonrotatable. Initially, a multiangle computational fluid dynamics-discrete element method gas-powder coupling model was established. It can consider not only the continuity characteristics of gas as a fluid, the discreteness characteristics of powder as particles, but also the mutual influence relationship. Subsequently, the response surface method was used to explore the optimal combination of carrier argon gas rate (A), the powder-feeding rate (B), and the protective argon gas rate (C) at different deflection angles, with the powder collection rate as the optimization objective. Analysis of variance results for the powder collection rate indicated that the significance of the factors and their interaction terms were ranked as A > B > AB at 0° and 30°, A > B > BC at 60°, A > B > C > BC at 90°, and C > A > BC > AB at 120° and 150°. Furthermore, the relative errors between predicted and simulated values, as well as simulated and powder collection experimental values, the single-pass experimental values were within 2%, 3%, and 7%, indicating the model was valid and reliable. Finally, the optimal combinations of carrier argon gas rate, powder-feeding rate, and protective argon gas rate were obtained, achieving high powder collection rates. These research findings offer theoretical guidance for selecting and optimizing process parameters in multiangle laser cladding.