Experimental investigation on wettability and capillary performance of ultrasonic modified grooved aluminum wicks

作者：Zhong, Guisheng; Tang, Yong; Ding, Xinrui^*; Chen, Gong; Li, Zongtao

来源：International Journal of Heat and Mass Transfer, 2021, 179: 121642.

DOI：10.1016/j.ijheatmasstransfer.2021.121642

• Ultra-thin flat heat pipe
• Aluminum groove
• Ultrasonic modification
• Porous microstructures
• Capillary performance

The grooved wick has a promising potential in the field of ultra-thin flat heat pipes, and the porous struc-ture can improve the capillary performance of grooved wicks significantly. In this paper, an environmen-tally friendly method, named as ultrasonic modification, was developed to fabricate porous microstruc-tures on grooved aluminum wick. The effects of ultrasonic modification times on the morphology, wetta-bility and capillary performance of the porous grooved wick were investigated. The results indicate that appropriate ultrasonic modification times can realize an excellent distribution of porous microstructures throughout the groove surface. After ultrasonic modification, the modified surface became hydrophobic since the porous microstructures were covered with a low-surface-energy coating. However, in case of aluminum heat pipes with acetone as working liquid, the wettability and capillary performance of the modified grooved wick can still be enhanced significantly. The maximum capillary rise height and the capillary performance parameter of the modified grooved wicks were increased for a factor of 3 and an order of magnitude, respectively. This study provides a new idea for the fabrication of porous aluminum wicks, which is beneficial to promote the development of ultra-flat aluminum heat pipes.