Temperature-based analysis of droplet cooling and freezing on femtosecond laser textured surfaces

Author(s):  
Yuan Wang ◽  
Pujun Zhao
Author(s):  
Lin Zhong ◽  
Gang Wei ◽  
Guo-rong Wang ◽  
Xia He ◽  
Yang Liao ◽  
...  

In this paper, the tribological characteristics of the unit tribo-pairs of rock bit sliding bearings under various loads and high temperatures were investigated. The conical textures, distributed in beryllium bronze surfaces with depth–diameter ratios ranging from 0.087 to 0.483, were fabricated using femtosecond laser irradiation. The friction characteristics of the 20CrNiMo/beryllium bronze tribo-pairs were tested at a high temperature of 120 ℃ and under non-Newtonian lubrication conditions using pin-on-disc configurations. The textured surfaces with depth–diameter ratios of 0.165 and 0.483 exhibited excellent lubrication and wear-resistant properties. In addition, the effects of the operating conditions on the tribological performance of the tribo-pairs were discussed.


Coatings ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 587 ◽  
Author(s):  
Annalisa Volpe ◽  
Caterina Gaudiuso ◽  
Leonardo Di Venere ◽  
Francesco Licciulli ◽  
Francesco Giordano ◽  
...  

Ice formation is a serious issue in many fields, from energy to aerospace, compromising the devices’ efficiency and security. Superhydrophobicity has been demonstrated to be correlated to the anti-icing properties of surfaces. However, fabricating surfaces with robust water repellence properties also at subzero temperature is still a great challenge. In this work, femtosecond laser (fs-laser) texturing is exploited to produce superhydrophobic surfaces with anti-icing properties on Al2024, an aluminum alloy of great interest in cold environments, in particular for aircraft production. Our textured substrates present self-cleaning properties and robust water repellency at subzero temperatures. Moreover, outstanding anti-icing properties are achieved on the textured surfaces at −20 °C, with water droplets bouncing off the surface before freezing.


2020 ◽  
Vol 92 (2) ◽  
pp. 20701
Author(s):  
Bo Li ◽  
Xiaofeng Li ◽  
Zhifeng Zhu ◽  
Qiang Gao

Laser-induced breakdown spectroscopy (LIBS) is a powerful technique for quantitative diagnostics of gases. The spatial resolution of LIBS, however, is limited by the volume of plasma. Here femtosecond-nanosecond dual-pulsed LIBS was demonstrated. Using this method, the breakdown threshold was reduced by 80%, and decay of continuous radiation was shortened. In addition, the volume of the plasma was shrunk by 85% and hence, the spatial resolution of LIBS was significantly improved.


2006 ◽  
Vol 223 (S 1) ◽  
Author(s):  
MP Holzer ◽  
TM Rabsilber ◽  
GU Auffarth

2012 ◽  
Vol 17 (1) ◽  
pp. 14-19
Author(s):  
Jae-Bong Lee ◽  
Joo-Hyun Moon ◽  
Seong-Hyuk Lee

2003 ◽  
Vol 780 ◽  
Author(s):  
R. Houbertz ◽  
J. Schulz ◽  
L. Fröhlich ◽  
G. Domann ◽  
M. Popall ◽  
...  

AbstractReal 3-D sub-νm lithography was performed with two-photon polymerization (2PP) using inorganic-organic hybrid polymer (ORMOCER®) resins. The hybrid polymers were synthesized by hydrolysis/polycondensation reactions (modified sol-gel synthesis) which allows one to tailor their material properties towards the respective applications, i.e., dielectrics, optics or passivation. Due to their photosensitive organic functionalities, ORMOCER®s can be patterned by conventional photo-lithography as well as by femtosecond laser pulses at 780 nm. This results in polymerized (solid) structures where the non-polymerized parts can be removed by conventional developers.ORMOCER® structures as small as 200 nm or even below were generated by 2PP of the resins using femtosecond laser pulses. It is demonstrated that ORMOCER®s have the potential to be used in components or devices built up by nm-scale structures such as, e.g., photonic crystals. Aspects of the materials in conjunction to the applied technology are discussed.


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