Cold Sprayed Boiling Enhancement Coating

The current investigation utilises cold spray technology to coat specimens which are experimentally tested to analyse pool boiling enhancement. The coatings are generatedf rom a 50/50 volume aluminium/copper feedstock powder mixture that is cold sprayed onto a copper substrate. After spraying, the aluminium content is etched, using NaOH, resulting in a surface with increased surface porosity, area and roughness. Characteristics of the surface are experimentally investigated to examine the surface wettability, roughness and wicking potential. Heat transfer measurements are recorded through the use of a pool boiling facility. Additional testing was carried out on an uncoated test sample and a pure copper powder cold sprayed coated sample for comparability. Findings demonstrate that the cold sprayed coatings initiate boiling at a lower wall superheat compared to an uncoated surface and achieve an increase critical heat flux threshold.