Lasered Roughness to Increase Wicking Rates in Pin-Fin Microstructure

2020 ◽  
Author(s):  
Sougata Hazra ◽  
Tanya Liu ◽  
Mehdi Asheghi ◽  
Kenneth Goodson
Keyword(s):  
Surface Roughness ◽  
Laser Ablation ◽  
Hybrid Structures ◽  
Laser Machining ◽  
Fast Method ◽  
Uv Laser ◽  
Strong Function ◽  
Pin Fin ◽  
Capillary Wicking

Abstract In this study, we demonstrate an inexpensive and fast method of creating hybrid microstructures for enhancement of capillary wicking by using UV laser ablation. We have also experimentally observed that capillary wicking rates are greatly increased by laser-machining induced surface roughness in pin-fin microstructures, and in one case the amount of enhancement was as large as 116%. The capillary wicking enhancement is a strong function of the geometry of the largescale pin-fin microstructures as well as the surface roughness of the flat areas. This study will help lead to the better understanding of capillary wicking in hybrid structures that in turn can assist with more informed designing and optimization processes of evaporator wicks in vapor chambers.

Micromachining Characteristics of Sapphire with Fifth HG Nd:YAG Laser

2007 ◽  
Vol 329 ◽  
pp. 589-594
Author(s):  
Toshiyuki Noji ◽  
Kazuo Nakamura ◽  
Hideyuki Horisawa ◽  
Nobuo Yasunaga
Keyword(s):  
Surface Roughness ◽  
Nd:Yag Laser ◽  
Smooth Surface ◽  
Short Pulse ◽  
Ultra Violet ◽  
Laser Wavelength ◽  
Bottom Surface ◽  
Laser Machining ◽  
Uv Laser ◽  
Sapphire Surface

In order to reduce the thermal influences in laser machining of sapphire surface, effects of a short-pulse ultra-violet laser were investigated. For the UV laser, the Fifth harmonic generation (Fifth HG) wave of an Nd:YAG laser (wavelength:213nm) was utilized. Significant reduction of thermal damages on the surface was demonstrated with the Fifth HG pulses compared to longer wavelengths of the Nd:YAG laser. It was shown that the control of depth of bottom surface with reduced thermal influences was possible in lower fluence cases(less than 40 J/cm2) with a homogenized beam and smooth surface roughness Ra < 200nm was obtainable.

High-Throughput Picosecond Laser Machining of Aerospace Nickel Superalloy

2021 ◽  
pp. 095440542110288
Author(s):  
Sundar Marimuthu ◽  
Bethan Smith
Keyword(s):  
Surface Roughness ◽  
Material Removal Rate ◽  
Material Removal ◽  
Thermal Damage ◽  
Removal Rate ◽  
Picosecond Laser ◽  
Nickel Superalloy ◽  
Laser Machining ◽  
Process Conditions ◽  
Machining Performance

This manuscript discusses the experimental results on 300 W picosecond laser machining of aerospace-grade nickel superalloy. The effect of the laser’s energetic and beam scanning parameters on the machining performance has been studied in detail. The machining performance has been investigated in terms of surface roughness, sub-surface thermal damage, and material removal rate. At optimal process conditions, a picosecond laser with an average power output of 300 W can be used to achieve a material removal rate (MRR) of ∼140 mm3/min, with thermal damage less than 20 µm. Shorter laser pulse widths increase the material removal rate and reduce the resultant surface roughness. High scanning speeds improve the picosecond laser machining performance. Edge wall taper of ∼10° was observed over all the picosecond laser machined slots. The investigation demonstrates that high-power picosecond lasers can be used for the macro-machining of industrial components at an acceptable speed and quality.

scholarly journals Lithography and Etching‐Free Microfabrication of Silicon Carbide on Insulator Using Direct UV Laser Ablation

2020 ◽  
Vol 22 (4) ◽  
pp. 1901173
Author(s):  
Tuan‐Khoa Nguyen ◽  
Hoang-Phuong Phan ◽  
Karen M. Dowling ◽  
Ananth Saran Yalamarthy ◽  
Toan Dinh ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Laser Ablation ◽  
Uv Laser

Nanoscale evaluation of surface roughness of metal films prepared by laser ablation

1998 ◽  
Vol 66 (7) ◽  
pp. S815-S818 ◽  
Author(s):  
T. Sumomogi ◽  
H. Sakai ◽  
M. Nakata ◽  
T. Endo
Keyword(s):  
Surface Roughness ◽  
Laser Ablation ◽  
Metal Films
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