Enhancement of Flow Boiling Heat Transfer Performance Using Single-Step Electrodeposited Cu-Al_2O_3 Nanocomposite Coating on Copper Substrate

摘要

The higher-thermal conductive Cu-Al2O3 nanoparticles are deposited on the copper surface by using single-step electrodeposition technique. The developed Cu-Al2O3 nanocomposite-coated surfaces attained excellent adhesiveness with copper substrate. Again, the surface morphology parameters like wettability, roughness, porosity, and porous layer thickness, as per the necessity in structured surfaces, can be easily managed by managing the electrodeposition parameters like potential difference, deposition time, current density, and electrolyte concentration. The surface morphology characterization is carried out with respect to the wettability, roughness, coating thickness, porosity, and average pore diameter. The flow boiling heat transfer experiments at different mass flow rates with deionized (DI) water are carried out in a minichannel of developed experimental setup. The Cu-Al2O3 coating offers lower thermal resistance due to its higher thermal conductivity and lower coating thickness. Again, the percentage enhancement in critical heat flux (CHF) and boiling heat transfer coefficient (BHTC) of the Cu-Al2O3-coated surfaces is decreased with the increase in mass flow rate, which is owing to the partial wetting of the pores at higher mass flow rate. The maximum augmentations in BHTC and CHF for the coated surfaces are achieved up to 84% and 86% as compared to the bare surface, respectively, which are due to the improvement in surface wettability and formation of huge number of cavities/pores on coated surfaces. Thus, the porous surface with minichannel is the potential candidate for the microelectronics cooling devices due to its compact size, lower heating surface temperature, higher CHF, and higher BHTC.