scholarly journals Improving Tribological Properties of Stainless Steel Surfaces by Femtosecond Laser Irradiation

Coatings ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 606
Author(s):  
Serguei P. Murzin ◽  
Valeriy B. Balyakin ◽  
Gerhard Liedl ◽  
Alexey A. Melnikov ◽  
Roland Fürbacher
Keyword(s):  
Stainless Steel ◽  
Femtosecond Laser ◽  
Laser Irradiation ◽  
Tribological Properties ◽  
Femtosecond Laser Irradiation ◽  
Test Scheme ◽  
Periodic Surface ◽  
Self Organized ◽  
The Coefficient Of Friction ◽  
Pin On Disk

A possibility of improving tribological properties by femtosecond laser irradiation on an example of a steel surface by creating regularly arranged micro-grooved textures that contain self-organized microstructures and nano laser-induced periodic surface structures (LIPSS) was determined. The friction coefficient of the treated surface of a sample of cold-rolled 1.4301 stainless steel was evaluated using a CSM Instruments SA tribometer according to a Pin-on-disk test scheme at a specific pressure of 1 MPa. It was found that the coefficient of friction was reduced by 35% compared to the initial grinded surface. Such laser treatment can find application for using parts in conditions of dry or boundary friction, mainly in units, in which the use of lubricant is unacceptable or extremely undesirable.

Submillimeter Micropart Feeding Along an Asymmetric Femtosecond-Laser-Microfabricated Surface

2009 ◽  
Vol 3 (2) ◽  
pp. 151-156 ◽  
Author(s):  
Atsushi Mitani ◽  
◽  
Shinichi Hirai ◽  
Keyword(s):  
Stainless Steel ◽  
Femtosecond Laser ◽  
Laser Irradiation ◽  
Periodic Structures ◽  
Friction Angle ◽  
Femtosecond Laser Irradiation ◽  
Laser Technology ◽  
Feed Velocity ◽  
Inclined Surfaces ◽  
The Relationship

Femtosecond laser technology forms minute, stable gratings on such materials as silicon and stainless steel. Forming a periodic structure on the surfaces of sliding parts improves tribology characteristics because adhesion decreases with reductions in area of contact. Double-pulsed femtosecond laser irradiation generates periodic structures with asymmetric profiles, along which, as we have shown elsewhere, microparts such as ceramic chip capacitors and resistors can be fed using simple symmetric planar vibration. Microparts move unidirectionally because they adhere to these surfaces asymmetrically. In testing the feasibility of feeding 0402 capacitors 0.4 × 0.2 × 0.2 mm in size and 0.1 mg weighting along an asymmetric surface fabricated using double-pulsed femtosecond laser irradiation, we evaluated differences in the profiles of the two inclined surfaces, effects of decreased adhesion, the forward and backward coefficient of friction, and the bidirectional friction angle of 0402 capacitors. Based on feed experimental results, we assessed the relationship between drive frequency and feed velocity and, by calculating variations in feed velocity, feed stability.

Ultrafast Laser Induced Subwavelength Periodic Surface Structures on Semiconductors/Metals and Application to SERS Studies

MRS Advances ◽  
2016 ◽  
Vol 1 (49) ◽  
pp. 3317-3327 ◽  
Author(s):  
V. Saikiran ◽  
Mudasir H Dar ◽  
R. Kuladeep ◽  
Narayana Rao Desai
Keyword(s):  
Femtosecond Laser ◽  
Laser Irradiation ◽  
Gold Film ◽  
Low Frequency ◽  
Surface Enhanced Raman Spectroscopy ◽  
Surface Structures ◽  
Femtosecond Laser Irradiation ◽  
Gold Films ◽  
Periodic Surface ◽  
Different Thickness

ABSTRACTIn this manuscript a simple approach is discussed to fabricate uniform periodic surface structures on semiconductor surfaces by femtosecond laser irradiation for surface-enhanced Raman spectroscopy (SERS) applications. Gold films having different thickness are first deposited on semiconductor silicon (Si) surfaces and then periodic surface structures are fabricated by femtosecond laser irradiation. The periodic structures are observed to be uniform over a large area with chain type structure formation of gold and Si. We have studied the formation of these surface structures on Si surface by having different thickness gold films deposited on Si substrates. This approach of the fabrication of surface structures with the assistance of gold film is found to help in local field enhancement and hence work as suitable substrate for the SERS experiments. The conditions for achieving high enhancement factor in SERS with different gold film thicknesses are explored in detail. We also present here the formation of low frequency ripples on Silicon (Si) and high frequency as well as low frequency ripples on titanium (Ti) surface in air and water environments by irradiation with fs laser pulses. Different morphologies were observed on Ti surface depending upon the laser irradiation parameters and the surrounding dielectric medium.

scholarly journals Fabricating Femtosecond Laser-Induced Periodic Surface Structures with Electrophysical Anisotropy on Amorphous Silicon

Nanomaterials ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 42
Author(s):  
Dmitrii Shuleiko ◽  
Mikhail Martyshov ◽  
Dmitrii Amasev ◽  
Denis Presnov ◽  
Stanislav Zabotnov ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Laser Irradiation ◽  
Volume Fraction ◽  
Femtosecond Laser Pulses ◽  
Surface Structures ◽  
Femtosecond Laser Irradiation ◽  
Nanocrystalline Phase ◽  
Near Surface ◽  
Periodic Surface ◽  
Relief Formation

One-dimensional periodic surface structures were formed by femtosecond laser irradiation of amorphous hydrogenated silicon (a-Si:H) films. The a-Si:H laser processing conditions influence on the periodic relief formation as well as correlation of irradiated surfaces structural properties with their electrophysical properties were investigated. The surface structures with the period of 0.88 and 1.12 μm were fabricated at the laser wavelength of 1.25 μm and laser pulse number of 30 and 750, respectively. The orientation of the surface structure is defined by the laser polarization and depends on the concentration of nonequilibrium carriers excited by the femtosecond laser pulses in the near-surface region of the film, which affects a mode of the excited surface electromagnetic wave which is responsible for the periodic relief formation. Femtosecond laser irradiation increases the a-Si:H films conductivity by 3 to 4 orders of magnitude, up to 1.2 × 10−5 S∙cm, due to formation of Si nanocrystalline phase with the volume fraction from 17 to 28%. Dark conductivity and photoconductivity anisotropy, observed in the irradiated a-Si:H films is explained by a depolarizing effect inside periodic microscale relief, nonuniform crystalline Si phase distribution, as well as different carrier mobility and lifetime in plane of the studied samples along and perpendicular to the laser-induced periodic surface structures orientation, that was confirmed by the measured photoconductivity and absorption coefficient spectra.

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