scholarly journals Direct Femtosecond Laser Fabrication of Superhydrophobic Aluminum Alloy Surfaces with Anti-icing Properties

Coatings ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 587 ◽  
Author(s):  
Annalisa Volpe ◽  
Caterina Gaudiuso ◽  
Leonardo Di Venere ◽  
Francesco Licciulli ◽  
Francesco Giordano ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Femtosecond Laser ◽  
Water Repellency ◽  
Subzero Temperature ◽  
Textured Surfaces ◽  
Cold Environments ◽  
Subzero Temperatures ◽  
Fs Laser ◽  
Aircraft Production ◽  
Water Repellence

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.

Double-pulse femtosecond laser peening of aluminum alloy AA5038: Effect of inter-pulse delay on transient optical plume emission and final surface micro-hardness

2016 ◽  
Vol 109 (21) ◽  
pp. 211902 ◽  
Author(s):  
E. I. Ageev ◽  
V. Yu. Bychenkov ◽  
A. A. Ionin ◽  
S. I. Kudryashov ◽  
A. A. Petrov ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Femtosecond Laser ◽  
Double Pulse ◽  
Laser Peening ◽  
Micro Hardness ◽  
Pulse Delay ◽  
Final Surface ◽  
Plume Emission

Fabrication and Characterization of Si Nano-Columns by Femtosecond Laser

2012 ◽  
Vol 16 ◽  
pp. 15-20 ◽  
Author(s):  
Omid Tayefeh Ghalehbeygi ◽  
Vural Kara ◽  
Levent Trabzon ◽  
Selcuk Akturk ◽  
Huseyin Kizil
Keyword(s):  
Laser Ablation ◽  
Femtosecond Laser ◽  
Laser Beam ◽  
Chemical Etching ◽  
Silicon Surface ◽  
Laser Pulses ◽  
Laser Beam Profile ◽  
Fs Laser ◽  
Fabrication And Characterization

We fabricated Si Nano-columns by a femtosecond laser with various wavelengths and process parameters, whilst the specimen was submerged in water. The experiments were carried out by three types of wavelengths i.e. 1030 nm, 515nm, 343nm, with 500 fs laser pulses. The scales of these spikes are much smaller than micro spikes that are constructed by laser irradiation of silicon surface in vacuum or gases like SF6, Cl2. The Si nano-columns of 300 nm or less in width were characterized by SEM measurements. The formation of these Si Nano-columns that were revealed by SEM observation, indicates chemical etching with laser ablation occurred when surface exposed by laser beam. We observed 200 nm spikes height at the center of laser beam profile and the ones uniform in height at lateral incident area.

Electronic Properties of Femtosecond Laser Induced Modified Spots on Single Crystal Silicon Carbide

2010 ◽  
Vol 645-648 ◽  
pp. 239-242 ◽  
Author(s):  
Takuro Tomita ◽  
M. Iwami ◽  
M. Yamamoto ◽  
M. Deki ◽  
Shigeki Matsuo ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Femtosecond Laser ◽  
Single Crystal ◽  
Specific Resistance ◽  
Single Crystal Silicon ◽  
Metal Contacts ◽  
Crystal Silicon ◽  
Current Voltage ◽  
Fs Laser ◽  
Current Voltage Characteristics

Femtosecond (fs) laser modification on single crystal silicon carbide (SiC) was studied from the viewpoints of electric conductivity. Fourier transform infrared (FTIR) spectroscopy was carried out on femtosecond laser modified area. The intensity decrease of reststrahlen band due to the modification was observed, and this decrease was explained by the degradation of crystallinity due to the laser irradiation. Polarization dependence of reststrahlen band was also observed on laser modified samples. Current-voltage characteristics and Hall measurements on fs-laser modified region were carried out by fabricating the metal contacts on the ion implanted areas. The specific resistance up to 5.9×10-2 m was obtained for fs-laser modified area.

A STUDY OF FEMTOSECOND LASER POLISHING OF CVD NANOPOLYCRYSTALLINE DIAMOND FILMS

2021 ◽  
pp. 2150023
Author(s):  
YU-XIAO CUI ◽  
PING GUO ◽  
XUEMING ZHU ◽  
YAN-LING TIAN ◽  
DA-WEI ZHANG ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Laser Fluence ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Laser Pulses ◽  
Promising Technique ◽  
Laser Polishing ◽  
Laser Fluences ◽  
Fs Laser ◽  
The Mean

Femtosecond (fs) laser ablation has been recognized as an effective and promising technique for high-precision processing of natural and synthesized diamond. In this work, a study of femtosecond laser polishing for nanopolycrystalline diamond (NCD) films by chemical vapor deposition (CVD) is reported. The laser irradiation is induced by 200-fs laser pulses with a repetition frequency of 50[Formula: see text]MHz, and various laser fluences are employed to investigate their polishing effectiveness. The results show that the optimal laser fluence is 0.7[Formula: see text]J/cm2, at which the nanodiamond grains on top of the cauliflower-like clusters of NCD films can be ablated. With such laser fluence, the mean surface roughness of NCD films reduces from 73.84[Formula: see text]nm to 31.88[Formula: see text]nm, which presents a 57% reduction. Nevertheless, when the laser fluence rises beyond 0.7[Formula: see text]J/cm2, large amount of amorphous carbon (a-C) balls and porous lava-like morphology would come into being, resulting in severe degradation of the NCD surface.

scholarly journals Femtosecond Laser Fabricated Elastomeric Superhydrophobic Surface with Stretching-Enhanced Water Repellency

2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Huan Yang ◽  
Kaichen Xu ◽  
Changwen Xu ◽  
Dianyuan Fan ◽  
Yu Cao ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Superhydrophobic Surface ◽  
Water Repellency ◽  
Superhydrophobic Surfaces ◽  
Textured Surface ◽  
Liquid Droplets ◽  
Silicone Elastomers ◽  
Highly Stretchable ◽  
First Time ◽  
Application Prospects

Abstract Highly stretchable and robust superhydrophobic surfaces have attracted tremendous interest due to their broad application prospects. In this work, silicone elastomers were chosen to fabricate superhydrophobic surfaces with femtosecond laser texturing method, and high stretchability and tunable adhesion of the superhydrophobic surfaces were demonstrated successfully. To our best knowledge, it is the first time flexible superhydrophobic surfaces with a bearable strain up to 400% are fabricated by simple laser ablation. The test also shows that the strain brings no decline of water repellency but an enhancement to the superhydrophobic surfaces. In addition, a stretching-induced transition from “petal” state to “lotus” state of the laser-textured surface was also demonstrated by non-loss transportation of liquid droplets. Our results manifest that femtosecond laser ablating silicone elastomer could be a promising way for fabricating superhydrophobic surface with distinct merits of high stretchability, tunable adhesion, robustness, and non-fluorination, which is potentially useful for microfluidics, biomedicine, and liquid repellent skin.

scholarly journals Preparation of Textured Surfaces on Aluminum-Alloy Substrates

Materials ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 109 ◽  
Author(s):  
Markéta Kadlečková ◽  
Antonín Minařík ◽  
Petr Smolka ◽  
Aleš Mráček ◽  
Erik Wrzecionko ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Tensile Testing ◽  
Chemical Etching ◽  
Etching Time ◽  
Textured Surface ◽  
Initial Surface ◽  
Textured Surfaces ◽  
Force Microscopy ◽  
Atomic Force ◽  
Time Period

The ways of producing porous-like textured surfaces with chemical etching on aluminum-alloy substrates were studied. The most appropriate etchants, their combination, temperature, and etching time period were explored. The influence of a specifically textured surface on adhesive joints’ strength or superhydrophobic properties was evaluated. The samples were examined with scanning electron microscopy, profilometry, atomic force microscopy, goniometry, and tensile testing. It was found that, with the multistep etching process, the substrate can be effectively modified and textured to the same morphology, regardless of the initial surface roughness. By selecting proper etchants and their sequence one can prepare new types of highly adhesive or even superhydrophobic surfaces.

scholarly journals Cold-stress responses in the Antarctic basidiomycetous yeast Mrakia blollopis

2016 ◽  
Vol 3 (7) ◽  
pp. 160106 ◽  
Author(s):  
Masaharu Tsuji
Keyword(s):  
Amino Acids ◽  
Cell Growth ◽  
Cold Stress ◽  
Stress Responses ◽  
Aromatic Amino Acids ◽  
Tca Cycle ◽  
Basidiomycetous Yeast ◽  
Subzero Temperature ◽  
Subzero Temperatures ◽  
The Antarctic

Microbes growing at subzero temperatures encounter numerous growth constraints. However, fungi that inhabit cold environments can grow and decompose organic compounds under subzero temperatures. Thus, understanding the cold-adaptation strategies of fungi under extreme environments is critical for elucidating polar-region ecosystems. Here, I report that two strains of the Antarctic basidiomycetous yeast Mrakia blollopis exhibited distinct growth characteristics under subzero conditions: SK-4 grew efficiently, whereas TKG1-2 did not. I analysed the metabolite responses elicited by cold stress in these two M. blollopis strains by using capillary electrophoresis–time-of-flight mass spectrometry. M. blollopis SK-4, which grew well under subzero temperatures, accumulated high levels of TCA-cycle metabolites, lactic acid, aromatic amino acids and polyamines in response to cold shock. Polyamines are recognized to function in cell-growth and developmental processes, and aromatic amino acids are also known to improve cell growth at low temperatures. By contrast, in TKG1-2, which did not grow efficiently, cold stress strongly induced the metabolites of the TCA cycle, but other metabolites were not highly accumulated in the cell. Thus, these differences in metabolite responses could contribute to the distinct abilities of SK-4 and TKG1-2 cells to grow under subzero temperature conditions.

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