Triangular laser-induced submicron textures for functionalising stainless steel surfaces

Applied Surface Science

Gülçür

García‐Girón

et al. 2019

Self Cite

CitationRomano J-M, Gülçür M, Garcia-Giron A et al (2019) Mechanical durability of hydrophobic surfaces fabricated by injection moulding of laser-induced textures. Applied Surface Science. 476: 850-860. Rights ABSTRACT.The paper reports an investigation on the mechanical durability of textured thermoplastic surfaces together with their respective wetting properties. A range of laser-induced topographies with different aspect ratios from micro to nanoscale were fabricated on tool steel inserts using an ultrashort pulsed near infrared laser. Then, through micro-injection moulding the topographies were replicated onto polypropylene surfaces and their durability was studied systematically. In particular, the evolution of topographies on textured thermoplastic surfaces together with their wetting properties were investigated after undergoing a controlled mechanical abrasion, i.e.reciprocating dry and wet cleaning cycles. The obtained empirical data was used both to study the effects of cleaning cycles and also to identify cleaning procedures with a minimal impact on textured thermoplastic surfaces and their respective wetting properties. In addition, the use of 3D areal parameters that are standardised and could be obtained readily with any state-of-the-art surface characterisation system are discussed for monitoring the surfaces' functional response.

Section: Laser Texturing Of Insertsmentioning

confidence: 99%

Mechanical durability of hydrophobic surfaces fabricated by injection moulding of laser-induced textures

Applied Surface Science

Gülçür

García‐Girón

et al. 2019

Self Cite

“…The following results are based on a preliminary study where a single raster scan was used to generate triangular LIPSS on steel surfaces [5]. Uniform triangles were obtained over relatively large area by varying the fluence per pulse (ϕ0) and the number of pulses (N).…”

Section: Experimental Set-upmentioning

confidence: 99%

“…The LIPSS seem to go through sharp morphological transitions under specific irradiation conditions, containing surprisingly uniform hexagonal alignments therebetween. While the mechanisms underlying LIPSS formations are yet to be fully understood, with such concepts put forward as surface-scattered interferences [11] or resonance of surface plasmon polaritons [12], circular polarisation is the main underlining reason for creating such hexagonal alignments [5]. A cartography of the low spatial frequency LIPSS is therefore presented in Figure 4.…”

Section: Fabrication Of Springtail-inspired Lipssmentioning

confidence: 99%

“…Both steel and titanium alloy samples exhibited similar ageing behaviours. For stainless steel, the maximum contact angle was measured at more than 155° after 7 days of storage in ambient air [5] or after the same amount of time in plastic bags (see Fig. 8c-d).…”

Section: Surface Functionalizationmentioning

confidence: 99%

“…Recently, laser micro manufacturing has reached a new milestone, enabling the controlled generation of highly regular Laser-Induced Periodic Surface Structures (LIPSS) on metals [4] and hexagonally-aligned submicron triangular features could be fabricated [5]. Such surface structures resembles the hexagonal comb-like pattern (see Fig.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Springtail-Inspired Triangular Laser-Induced Surface Textures on Metals Using MHz Ultrashort Pulses

Journal of Micro and Nano-Manufacturing

Helbig

Fraggelakis

et al. 2019

Self Cite

Considering the attractive surface functionalities of springtails (Collembola), an attempt at mimicking their cuticular topography on metals is proposed. An efficient single-step manufacturing process has been considered, involving laser-induced periodic surface structures (LIPSS) generated by near-infrared femtosecond laser pulses. By investigating the influence of number of pulses and pulse fluence, extraordinarily uniform triangular structures were fabricated on stainless steel and titanium alloy surfaces, resembling the primary comb-like surface structure of springtails. The laser-textured metallic surfaces exhibited hydrophobic properties and light scattering effects that were considered in this research as a potential in-line process monitoring solution. The possibilities to increase the processing throughput by employing high repetition rates in the MHz-range are also investigated.

Design Rules for Laser‐Treated Icephobic Metallic Surfaces for Aeronautic Applications

Vercillo

Tonnicchia

et al. 2020

Adv Funct Materials

113

Ice accretion on external aircraft surfaces due to the impact of supercooled water droplets can negatively affect the aerodynamic performance and reduce the operational capability and, therefore, must be prevented. Icephobic coatings capable of reducing the adhesion strength of ice to a surface represent a promising technology to support thermal or mechanical ice protection systems. Icephobicity is similar to hydrophobicity in several aspects and superhydrophobic surfaces embody a straightforward solution to the ice adhesion problem. Short/ultrashort pulsed laser surface treatments are proposed as a viable technology to generate superhydrophobic properties on metallic surfaces. However, it has not yet been verified whether such surfaces are generally icephobic under representative icing conditions. This study investigates the ice adhesion strength on Ti6Al4V, an alloy commonly used for aerospace components, textured by means of direct laser writing, direct laser interference patterning, and laser-induced periodic surface structures laser sources with pulse durations ranging from nano-to femtosecond regimes. A clear relation between the spatial period, the surface microstructure depth, and the ice adhesion strength under different icing conditions is investigated. From these observations, a set of design rules can be defined for superhydrophobic surfaces that are icephobic, too.can reduce dramatically lift and increase drag, influencing the maneuverability of the aircraft. Ice protection systems (IPS) are installed to allow aircraft flying safely in icing conditions. At the present time, IPS are not supported by coatings or surfaces that facilitate the ice removal-due to the still too low maturity and robustness of such technological solutions. Yet, surface functionalization is a promising strategy for manufacturing icephobic surfaces [3] aiming to delay ice accretion and/ or to reduce ice adhesion [4,5] and therefore to reduce the electrical or thermal energy required by the IPS.In the last two decades, several approaches for producing icephobic surfaces were presented in literature. For example, it has been proven that polishing the surfaces can reduce the mechanical interlocking with the accreted ice, hence facilitating the ice removal. [5] Coatings can lower the surface free energy and thus reduce the strength of the bonding between ice and surface. [6] On slippery liquid-infused porous surfaces the supercooled water droplets impinge on a liquid instead of a solid surface, which offers a double advantage: interfacial slippage of water or ice occurs (nonzero slip velocity)-which reduces ice adhesion [7] -and interlocking of ice with a liquid interface cannot occur. However, employing coatings or chemicals to