Role Of Precursor Properties In Cold Spray Coating Process

The cold spray bonding process relies on high strain-rate plastic deformation. Unlike other spray techniques, initial as well as the dynamic physical property of the precursor will influence deposition. Irregular powders have shown to improve deposition efficiency. While beneficial increase in particle velocity due to better drag characteristics has been established as the underlying phenomenon, the influence of their initial physical property hasn’t attracted much attention. The variation in the initial physical arises from diverse atomization and attrition production routes. In order to distinguish the role of morphology and initial physical property in spherical and irregular powders, a fluidized bed setup to anneal the powders is developed. The annealing process leads to uniform physical properties for both powders. While higher deposition efficiency is achieved with irregular powders, the coating hardness tends to be lower. Correlations are derived from wear, bond and corrosion tests. Further swipe tests and electron back scattered diffraction analysis are carried out and a detailed assessment is presented.