Characterisation and corrosion studies of cold sprayed copper coatings on ASTM B 435 alloy

In this research paper, copper coatings were successfully deposited on Ni alloy (ASTM B 435) substrate using cold spray process with an aim to avoid the contact of dissimilar materials frequently encountered in industrial applications. The coatings were deposited using air as carrier gas by varying process parameters, i.e., powder feed type, stagnation temperature, stagnation pressure and stand-off distance. The deposited coatings were characterised using the combined techniques of XRD, FESEM, EDS and EPMA. EDAX, XRD and EPMA. It is found that the main constituent in the coating is Cu which resembles the sprayed powder used for the study. The developed coatings have a uniform and dense microstructure, with uniform hardness value in the range of 108-140 Hv, average coating thickness 13-58 mils and average surface roughness 6-11 mu m. A very small fraction of phases of other elements have formed in the microstructure of the coating in the form of either inter-splat lamellae or globules.