Influence of Co-Flow Nozzle Configuration on Particle Dynamics in a Low-Pressure Cold Spray Additive Manufacturing Process

Cold spray (CS) additive manufacturing is a solid-state deposition technique commonly used for both component repair and fabrication. In this process, converging-diverging nozzles are utilized to accelerate particles to high velocities, enabling their deposition onto a substrate. This study focuses on analyzing particle dynamics within a low-pressure CS system. In such systems, the lower particle velocities typically result in deposition efficiencies of less than 30%. Turbulent mixing of the plume with the surrounding atmosphere causes smaller particles to disperse and eject from the plume, resulting in lower deposition quality. Implementing a co-flow configuration helps shift the mixing zone away from the center of the plume, thereby reducing the turbulence effects on particle trajectories. A large-eddy simulation model is used to simulate the flow field, while a discrete phase model is employed for particle tracking. An improved particle drag model, incorporating high Mach number corrections, is utilized to more accurately capture particle dynamics within the flow. The results indicate a reduction in particle dispersion for the given system.

*This research was sponsored by the U.S. Army Combat Capabilities Development Command Army Research Laboratory and was accomplished under Cooperative Agreement Number W911NF-20-2-0163. The U.S. Government is authorized to reproduce and distribute reprints for Government purposes notwithstanding any copyright notation herein.