摘要
Nucleate pool boiling is highly effective for cooling high-power electronic devices and microsystems. In this work, a superhydrophilic dendritic-bush-shaped coating was electrodeposited on Cu substrates as boiling enhancement structures (BES). By varying H2SO4 and H3BO3 concentrations in the electrolyte, porous Cu films with different thicknesses and morphologies were obtained. Pool boiling experiments measured the critical heat flux (CHF) and heat transfer coefficient (HTC), while a contact angle analyzer and capillary rise tests evaluated the wettability and wicking properties. A distinct boiling inversion phenomenon was observed for porous Cu films with optimized structural parameters. High-speed imaging of bubble nucleation, growth, and departure revealed the link between surface architecture, bubble dynamics, and heat transfer performance. The optimized dendritic Cu structure achieved a CHF of 216 W/cm2 and an HTC of 24.6 W/cm2K, corresponding to enhancements of 125 % and 473 % over flat Cu. These findings highlight the promise of electrodeposited dendritic-bush structures for heat dissipation enhancement through nucleate pool boiling.
•Cu film morphology tailored by tuning CuSO4–H2SO4–H3BO3 electrolyte composition.•Boiling heat transfer performance enhanced by a boiling inversion phenomenon.•Effect of boiling enhancement structures (BES) on boiling inversion is analyzed.•An optimized BES achieves a CHF of 216 Wcm−2 and an HTC of 24.6 Wcm−2 K−1.•Bubble dynamics of boiling surfaces analyzed by high-speed imaging.