Advanced Nanostructured Powders for Cold Spray Applications

In this project, Eltron will develop a method for spray drying agglomerates of nanoparticles for use in the cold spray process. These agglomerates will allow the nanoparticles to be cold sprayed, resulting in coatings and structures with superior strength and hardness. Nanosized particles will be dispersed in a solvent with a metallic binder precursor and spray dried under controlled atmosphere to form spheroid particles. In the spray dryer, slurry droplets are expelled from the atomizer and the liquid surface tension creates perfect spheres. As the droplets fall through the spray dryer, the heated gas will simultaneously cause the liquid to evaporate and convert the binder precursor. As the liquid is removed, the nanoparticles are brought into contact, forming agglomerates while maintaining their spherical shape. When exposed to the spray dryer conditions, the binder precursor will form small crystals, coating the nanoparticles to form connections between the nanoparticles and fill the gaps between nanoparticles. New methods for forming platelets and needles will be developed by controlling spray drier settings and using an impact barrier. In addition, this technology will be directly transferable to agglomerating ceramic (WC, ZrO2, or VN) nanoparticles with a binder for wear-resistant cold spray commercial applications.