scholarly journals Creation of Superhydrophobic and Superhydrophilic Surfaces on ABS Employing a Nanosecond Laser

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2547 ◽  
Author(s):  
Cristian Lavieja ◽  
Luis Oriol ◽  
José-Ignacio Peña
Keyword(s):  
Acrylonitrile Butadiene Styrene ◽  
Laser Pulses ◽  
Green Laser ◽  
Contact Angles ◽  
Material Surface ◽  
Nanosecond Laser ◽  
Focal Position ◽  
Superhydrophilic Surface ◽  
Wetting Behaviors ◽  
Superhydrophilic Surfaces

A nanosecond green laser was employed to obtain both superhydrophobic and superhydrophilic surfaces on a white commercial acrylonitrile-butadiene-styrene copolymer (ABS). These wetting behaviors were directly related to a laser-induced superficial modification. A predefined pattern was not produced by the laser, rather, the entire surface was covered with laser pulses at 1200 DPI by placing the sample at different positions along the focal axis. The changes were related to the laser fluence used in each case. The highest fluence, on the focal position, induced a drastic heating of the material surface, and this enabled the melted material to flow, thus leading to an almost flat superhydrophilic surface. By contrast, the use of a lower fluence by placing the sample 0.8 µm out of the focal position led to a poor material flow and a fast cooling that froze in a rugged superhydrophobic surface. Contact angles higher than 150° and roll angles of less than 10° were obtained. These wetting behaviors were stable over time.

scholarly journals Alterations in the microhardness of a titanium alloy affected to a series of nanosecond laser pulses

2019 ◽  
Vol 298 ◽  
pp. 00051 ◽  
Author(s):  
Ivan Ushakov ◽  
Yuri Simonov
Keyword(s):  
Titanium Alloy ◽  
Laser Pulse ◽  
Laser Processing ◽  
Crack Formation ◽  
Laser Pulses ◽  
Hardened Layer ◽  
Material Surface ◽  
Nanosecond Laser ◽  
Plastic Properties ◽  
Geometrical Pattern

The alterations in the microhardness of a titanium alloy Ti85.85Al6.5Zr4Sn2Nb1Mo0.5Si0.15 subjected to laser treatment were investigated. Laser processing consists of a series of pulses with durations 20 ns. We used various methods of laser processing, which differed in power density, wavelength, geometrical pattern of irradiation and so on. The dependences of the microhardness on the load on the indenter were found. The laser processing modes providing the increased microhardness are determined. The investigations were carried out at loads from 0.49 N to 4.9 N, with maximum indentation depth of the Vickers pyramid up to 12 μm. Vickers microhardness can be increased by 20 – 40 %. At the same time, the plastic properties of the hardened layer are improved. The probability of crack formation during indentation of the initial alloy increased with a load on the indenter and reached 0.52 for a load of 4.9 N. In two of the treated areas of the three presented, crack formation was not recorded at any load. The mechanisms of hardening of the material surface layer under the influence of a laser pulse are discussed. Using the methods of computational mathematics, the character of sample heating under the influence of a single laser pulse is determined. The perspectives for the development of the proposed processing method are permitting to obtain the optimal mechanical properties of the hardened layer are discussed.

scholarly journals Study on contact angles and surface energy of MXene films

RSC Advances ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 5512-5520
Author(s):  
Hang Zhou ◽  
Fuqiang Wang ◽  
Yuwei Wang ◽  
Changping Li ◽  
Changrui Shi ◽  
...  
Keyword(s):  
Surface Energy ◽  
Contact Angles ◽  
Time Dependent ◽  
Wetting Behaviors

This work sheds light on the process- and time-dependent wetting behaviors and surface energy of MXene films.

Formation of Periodical Sub-Micron Sized Structures on Silicon by Interfered Nanosecond Laser Pulses

2010 ◽  
Vol 97-101 ◽  
pp. 3803-3806
Author(s):  
Yong Xiang Hu ◽  
Heng Zhang ◽  
Zheng Qiang Yao
Keyword(s):  
Cost Effective ◽  
Laser Pulses ◽  
Laser Beams ◽  
Nanosecond Laser ◽  
Effective Technique ◽  
First Order ◽  
Direct Fabrication ◽  
Cost Effective Technique ◽  
Nanosecond Laser Pulses ◽  
Micro Structuring

Laser interference micro-structuring is a relatively efficient and cost-effective technique for fabricating periodical micro-nano-structuring surfaces. The direct fabrication of sub-micron sized dot array on silicon was performed by four interfering nanosecond laser beams with a diffractive beam splitter. The mechanism to form the dot array was analyzed and it was found that the obtained conical dot array had a negative shape of the interference pattern of four laser beams. A second-order peak between two first-order peaks also occurred due to the liquid-solid expansion.

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