T. Kairet, Université Libre de Bruxelles, Bruxelles, Belgium; G. Di Stefano, M. Degrez, Université Libre de Bruxelles, Nivelles, Belgium; F. Campana, J. P. Janssen, Advanced Coating, LIEGE, Belgium
Cold sprayed copper coatings have been widely studied but the effect of substrate properties and spraying conditions on the bond strength still needs further investigations. Using nanoindentation, it is possible to compare the effect of spray parameters on the change in hardness on the powder before and after deposition. Deposition of 2 copper powders on aluminium and Ta6V substrates has been done at different stagnation temperatures and pressure using nitrogen. The effect of the grain size distribution on the deposit efficiency and the mechanical properties of the coating are discussed .Hardness profiles show how the speed of the particles induces shot peenning the surface. The interaction between the hot gas jet and the surface may recristallise the surface of the copper. The effect on the substrate hardness has also been investigated.
Summary: two copper powders with different grain sizes have been deposited. We discuss the effect of grain size and powder properties on the mechanical properties of the coatings. Nanoindentation has been used to characterize the coating and it offers an insight on how the spray conditions affect the hardness profile.
