Investigation on fabrication and capillary performance of multi-scale composite porous wick made by alloying-dealloying method

The multi-scale composite porous wick (MCPW) was fabricated with alloying-dealloying mehtod for the application in the two-phase heat transfer device. The nanostructures were constructed on the sintered copper powders, resulting in the change of surface topography and wettability for MCPW. The capillary rise test was conducted to study the capillary performance based on the IR thermal imaging method. In this study, the comparisons of the two kinds of copper powders and two types of corrosive solutions were conducted to explore porous structure effects and the interactions between the microstructures and nanostructures. Three different working liquids, i.e., acetone, ethanol and water were performed and compared on the MCPW and sintered wick. Test results showed that the MCPW presented hydrophilic performance, facilitating the penetration of the working fluid into the pores. Capillary performance could be significantly enhanced owing to the nanostructures, especially for the sample sintered with irregular copper powder and deallyed by NaOH solution.