Fabrication and capillary characterization of axially micro-grooved wicks for aluminium flat-plate heat pipes

A novel micro V-grooves wick, fabricated by ploughing-extrusion (P-E) method and then surface treated by chemical corrosion, was developed for enhancing the performance of aluminium flat-plate heat pipes (AFHPs). Capillary rise tests with acetone were performed to characterize the capillary performance of the wick structures. An infrared (IR) thermal imaging method was utilized to monitor the capillary rise processes. The effects of solution concentration and corrosion time on the capillary performance of the wicks were investigated. Experimental results indicate that the capillary rise height of the corroded aluminium grooved wicks was substantially higher than that of non-corroded wick. However, the concentration and corrosion time are to be regulated with care in order to achieve optimum capillary performance. In this study, the optimal corrosion parameters were determined to be 1.5 mol/L NaOH for 10 min, which resulted in the best capillary performance parameter (K/Reff) of 6.98 µm-an increase of approximately 207% compared to the one with no corrosion. This study demonstrates that the combination of P-E process and chemical corrosion method is a convenient and effective means to enhance the capillary performance of grooved aluminium wicks and the heat transport capability of AFHPs.