Functionalized interfaces enhancing phase-change processes have immense applicability in thermal management. Here, a methodology for fabrication of surfaces enabling extreme boiling heat transfer performance is demonstrated, combining direct nanosecond laser texturing and chemical vapor deposition hydrophobic fluorinated silane. Multiple strategies are explored on aluminum with subsequent nanoscale hydrophobization. Both superhydrophilic superhydrophobic laser-engineered microcavities...

The aim of this work was to show that with the use surface roughness parameters Ssk and Sku we can predict tribological behavior contact surfaces these plan texturing. This article presents a continuation our research on virtual texturing experimental textures in form channels. For investigation, steel samples were laser textured shape dimples different spacings between dimple depths. results confirmed be used design texturing, where higher value more negative lead lower friction.

High-intensity light from a laser pulse can produce optical breakdown in liquid, followed by shock wave and the growth of cavitation bubble. When bubble reaches its maximum radius liquid pressure causes it to collapse, which turn initiates another The oscillations repeat themselves several times, is emitted after every collapse. In our study was induced distilled water Nd:YAG pulsed laser, designed for ocular photodisruption. main focus experiments measurement waves using an probe based on...

When a high-intensity laser pulse is focused into liquid the energy converted mechanical via an optodynamic process. The conversion starts with plasma formation; this followed by shock-wave propagation and expansion of cavitation bubble. A bubble developed near boundaries results in asymmetrical collapse, generation jet during bubble’s rebound. In case free surface directed away from oscillation times are prolonged. On other hand, rigid boundary, toward boundary shortened. We present...

Nucleate boiling enables effective cooling and heat transfer at low temperature differences between a heated surface the surrounding fluid. It is utilized in many applications, ranging from large power plants to small microelectronics. To enhance process by minimization of increase maximum attainable flux, several approaches for modifications were recently developed. However, each them has least one important drawback, including challenging expensive production, mechanical and/or thermal...

Controlling the surface wettability represents an important challenge in field of functionalization. Here, a stainless-steel is modified by 30-ns pulses Nd:YAG marking laser (λ = 1064 nm) with peak fluences within range 3.3⁻25.1 J cm-2. The short- (40 days), intermediate- (100 days) and long-term (1 year) superhydrophilic-to-(super)hydrophobic transition laser-textured surfaces exposed to atmospheric air examined evaluating its context following parameters: (i) pulse fluence; (ii) scan line...

Laser-textured surfaces enabling reversible wettability switching and improved optical properties are gaining importance in cutting-edge applications, including self-cleaning interfaces, tunable lenses, microfluidics, lab-on-chip systems. Fabrication of such by combining nanosecond-laser texturing low-temperature annealing titanium Ti-6Al-4V alloy was demonstrated Lian et al. ACS Appl. Mater. Inter. 2020, 12 (5), 6573–6580. However, it is difficult to agree with (i) their contradictory...

In this work, we studied the wall heat flux partitioning during pool boiling of water on thin metallic surfaces. We conducted experiments surfaces where engineered nucleation sites by nanosecond-fiber-laser texturing. These form triangular lattice patterns with different pitches. measured time-dependent temperature and distributions surface using an infrared camera. developed post-processing algorithms to measure, based these distributions, all fundamental parameters used in models (e.g.,...

The influence of quadrature phase shift on the measured displacement error was experimentally investigated using a two-detector polarizing homodyne laser interferometer with detection system. Common nonlinearities, including phase-shift error, were determined and effectively corrected by robust data-processing algorithm. perfectly agrees theoretically region. This is systematic, periodic severely asymmetrical around nominal value. main results presented in this paper can also be used to...

When an erbium-laser pulse is directed into water through a small-diameter fiber tip (FT), the absorption of laser energy superheats and its boiling induces vapor bubble. We present influence different FT geometries parameters on vapor-bubble dynamics. In our investigation, we use free-running erbium: yttrium aluminum garnet (Er:YAG) (λ = 2.94 μm) that was designed for dentistry. Its FTs with flat conical geometry. Our results show in case FT, spherical bubble induced, while channel-like...

In this work, we present functionalization of AISI 316 L surfaces by nanosecond Nd:YAG laser texturing and adsorption superhydrophobic fluoroalkylsilane functionalized 30-nm silica nanoparticles. Surface modification varying the distance between laser-produced micro(μ)-channels leads to different surface roughnesses. After nanosilica coating, superhydrophilic laser-textured change into with same μ-roughness. A higher μ-channel density more hydrophobic after coating. This enables a study...

Nucleate pool boiling experiments were performed on plain and five laser-textured stainless-steel foils using saturated pure water, 100% ethanol, 0.4% 4.2% mole fraction ethanol – water mixtures. All samples contained untreated, smooth 0.5 mm wide regions intermediate textured surfaces, that differ in the width of laser patterned (from to 2.5 mm). For we measured significant decreases average heat transfer coefficients (HTC) increases bubble activation temperatures comparison with surfaces...

In this paper, we investigate the influence of following parameters: pulse duration, repetition rate, line-to-line and pulse-to-pulse overlaps, scanning strategy on ablation AISI 316L steel CuZn37 brass with a nanosecond, 1064-nm, Yb fiber laser. The results show that material removal rate (MRR) increases monotonically duration up to characteristic (f0) where energy average power are maximal. maximum MRR is reached at equal or slightly higher as f0. exact value depends correlation between...

We describe a high-speed, two-frame shadowgraph method for the two-dimensional visualization of an expanding laser-induced plasma and shock wave in two time instances. The developed experimental uses 30 ps, green-laser, polarized pulse direct delayed illumination separated by variable delay range from 300 ps to ns. Since exposed images single event are captured with CCD cameras, established enables velocity measurements fast phenomena within nanosecond excitation-laser as well at later...