Direct Metal Forming of a Microdome Structure with a Glassy Carbon Mold for Enhanced Boiling Heat Transfer

The application of microtechnology to traditional mechanical industries is limited owing to the lack of suitable micropatterning technology for durable materials including metal. In this research, a glassy carbon (GC) micromold was applied for the direct metal forming (DMF) of a microstructure on an aluminum (Al) substrate. The GC mold with microdome cavities was prepared by carbonization of a furan precursor, which was replicated from the thermal reflow photoresist master pattern. A microdome array with a diameter of 8.4 μm, a height of ~0.74 μm, and a pitch of 9.9 μm was successfully fabricated on an Al substrate by using DMF at a forming temperature of 645 °C and an applied pressure of 2 MPa. As a practical application of the proposed DMF process, the enhanced boiling heat transfer characteristics of the DMF microdome Al substrate were analyzed. The DMF microdome Al substrate showed 20.4 ± 2.6% higher critical heat flux and 34.1 ± 5.3% higher heat transfer coefficient than those of a bare Al substrate.

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Model-based experimental analysis of enhanced boiling heat transfer by micro-nano porous surfaces

Applied Thermal Engineering ◽

10.1016/j.applthermaleng.2021.116809 ◽

2021 ◽

pp. 116809

Author(s):

Min Hong ◽

Haoran Lu ◽

Jiu Luo ◽

Jianghang Gu ◽

Dongchuan Mo ◽

...

Keyword(s):

Heat Transfer ◽

Experimental Analysis ◽

Boiling Heat Transfer ◽

Model Based ◽

Porous Surfaces ◽

Enhanced Boiling

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Enhanced boiling heat transfer in mesochannels

International Journal of Heat and Mass Transfer ◽

10.1016/j.ijheatmasstransfer.2009.07.022 ◽

2009 ◽

Vol 52 (25-26) ◽

pp. 5802-5813 ◽

Cited By ~ 2

Author(s):

John D. Schwarzkopf ◽

Steven G. Penoncello ◽

Prashanta Dutta

Keyword(s):

Heat Transfer ◽

Boiling Heat Transfer ◽

Enhanced Boiling

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Thermal Bubble Dynamics Under the Effect of Acoustic Vibration

ASME 2009 7th International Conference on Nanochannels, Microchannels and Minichannels ◽

10.1115/icnmm2009-82085 ◽

2009 ◽

Author(s):

Xiaopeng Qu ◽

Huihe Qiu

Keyword(s):

Heat Transfer ◽

Acoustic Field ◽

Vapor Bubble ◽

Boiling Heat Transfer ◽

High Speed ◽

Bubble Dynamics ◽

Acoustic Vibration ◽

Micro Electro Mechanical System ◽

Mems Technology ◽

Enhanced Boiling

The effect of acoustic field on the dynamics of micro thermal bubble is investigated in this paper. The micro thermal bubbles were generated by a micro heater which was fabricated by standard Micro-Electro-Mechanical-System (MEMS) technology and integrated into a mini chamber. The acoustic field formed in the mini chamber was generated by a piezoelectric plate which was adhered on the top side of the chamber’s wall. The dynamics and related heat transfer induced by the micro heater generated vapor bubble with and without the existing of acoustic field were characterized by a high speed photograph system and a micro temperature sensor. Through the experiments, it was found that in two different conditions, the temperature changing induced by the micro heater generated vapor bubble was significantly different. From the analysis of the high speed photograph results, the acoustic force induced micro thermal bubble movements, such as forcibly removing, collapsing and sweeping, were the main effects of acoustic enhanced boiling heat transfer. The experimental results and theoretical analysis were helpful for understanding of the mechanisms of acoustic enhanced boiling heat transfer and development of novel micro cooling devices.

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