Preliminary study on deposition of aluminium and copper powders by cold spray micronozzle using helium

In general, the cold spray technique is applied for depositing coatings from powders of metals and alloys with 10–100 μm particle size. A typical exit diameter of a cold spray axisymmetric nozzle ranges between 5 and 10 mm that determines the spatial resolution of cold spray. Smaller nozzle exit diameters would provide a greater spatial resolution. In this study, micronozzles with 0.5 mm throat diameter and 1 mm exit diameter were applied for cold spraying aluminium and copper powders. Numerical simulation and experimental results on the application of micronozzles showed that fine (25 μm and finer) aluminium and copper particles could be accelerated to their critical velocities. Aluminium and copper 1 mm-width coatings were deposited.