Cold spraying of in situ produced TiB2–Cu nanocomposite powders

The goal of this work was to study the development of microstructure of the coatings cold sprayed from nanocomposite powders TiB2–43 vol.%-Cu containing titanium diboride particles 50–100 nm in size. Titanium diboride phase was in situ produced in a copper matrix using high-energy mechanical milling of Ti, B and Cu powders and self-propagating high-temperature synthesis. The coatings were fabricated on a copper substrate. The microstructure of the coatings was studied by scanning electron microscopy and energy dispersive spectroscopy. Due to low-temperature conditions of spraying, nanostructured coatings were produced retaining the microstructure of the nanocomposite powder being sprayed. Despite the high content of titanium diboride and the difference in plasticity of the phases, the coatings were fully dense and composed of closely packed powder particles. Considering the results of this study, cold spraying of nanocomposite mechanically milled powders can be recommended as a promising way for fabrication of nanostructured coatings.