Properties of Copper Coatings Obtained by Cold Gas Dynamic Spraying Using Helium: Influence of the Oxide Content of the Powder

Two copper powders with a different size distribution were sprayed on to an aluminium substrate using the cold gas dynamic spraying technique. Both powders were sprayed at a fixed helium pressure but two gas temperature were investigated: ambient and 200°C. The oxide content of both powder and coatings have been measured and compared. The influence of the oxide content of the powder will be discussed based on metallurgical characterization (optical microscopy, SEM,…) , microhardness measurement, powder speed measurements (using a DPV/CPS 2000 system), deposition efficiency comparison, the dislocation density in the coatings have been measured using the modified Hall-Williamson and Warren-Averbach calculation method. The influence of the oxide shell on the deformation behaviour of the powder during the coating formation leads to different dislocation densities in the coating.