Heat transfer enhancement of polished laser-textured copper surfaces in saturated pool boiling

Sugumaran, Luvindran and Mohd Zubir, Mohd Nashrul and Newaz, Kazi Salim and Tuan, Zaharinie and Mt Aznam, Suazlan and Mohd Halil, Aiman and Shekh, Abdullah and Shaikh, Kaleemullah and Ahmad, Norhafizan (2026) Heat transfer enhancement of polished laser-textured copper surfaces in saturated pool boiling. Case Studies in Thermal Engineering, 84 (NA). pp. 1-19. E-ISSN 2214-157X

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Abstract

Optimizing pool boiling heat transfer is essential for the thermal management of high-power electronics and energy systems. This study investigates the enhancement of boiling performance on copper surfaces through a dual-step laser processing technique: initial micro-texturing followed by a precision laser-polishing refinement. The boiling characteristics were evaluated for three surfaces: bare copper (BS), unpolished laser-textured (L1D1-X), and laser-polished (L1D1). While initial laser texturing increased the density of nucleation sites, redeposited nanometal lumps at the micropillar edges on the L1D1-X surface created a locally hydrophobic state (130.29°). This acted as a capillary barrier, hindering liquid droplets from entering the microchannels and replenishing the heated base. The secondary laser-polishing step (L1D1) resolved this by removing these edge-lumps, effectively restoring the hydrophilic state (44.72°) and microchannel accessibility. This transition enabled vigorous capillary wicking and rapid liquid replenishment, leading to a significant reduction in wall superheat. At a heat flux of 500 kW/m2, the L1D1 surface achieved a wall superheat of only 5.4°C and a heat transfer coefficient (HTC) of 93 kW/m2 K, representing an improvement of 93.8% over the bare surface and 32.9% over the unpolished textured surface. High-speed visualization confirmed that restoring channel patency facilitated superior bubble dynamics with an average departure frequency of 54 Hz. These findings establish laser polishing as a critical post-treatment for maximizing heat transfer efficiency by unlocking the capillary potential of engineered microstructures.

Item Type:	Article (Journal)
Uncontrolled Keywords:	Capillary wicking, Heat transfer enhancement, Laser texturing, Laser polishing, Pool boiling, Surface wettability
Subjects:	T Technology > T Technology (General) > T55.4 Industrial engineering.Management engineering. > T58.7 Production capacity. Manufacturing capacity T Technology > TJ Mechanical engineering and machinery T Technology > TP Chemical technology > TP155 Chemical engineering T Technology > TS Manufactures > TS200 Metal manufactures. Metalworking
Kulliyyahs/Centres/Divisions/Institutes (Can select more than one option. Press CONTROL button):	Kulliyyah of Engineering > Department of Manufacturing and Materials Engineering Kulliyyah of Engineering
Depositing User:	Dr. Suazlan Mt Aznam
Date Deposited:	29 Jun 2026 09:26
Last Modified:	29 Jun 2026 11:38
URI:	http://irep.iium.edu.my/id/eprint/129277

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