Search

Polymers are versatile materials widely used in various industries, with significant applications in biomedicine where biofouling on polymer surfaces presents major health and economic challenges. Biofouling, initiated by bacterial adhesion, can be mitigated by modifying surface properties through laser micro- and nano-texturing, an approach that offers advantages over chemical treatments. This study introduces an economical mass production process for textured polymeric components using injection molding to replicate hierarchical textures. Testing revealed that all textured samples significantly reduced bacterial adhesion compared to untextured surfaces across different designs and bacteria types after 24 h of culture. The study examined factors like wettability, nanoscale roughness, and pattern dimensions to explain these outcomes, comparing them with existing studies. Despite all textured samples showing decreased wettability and roughness, these factors alone did not ensure reduced bacterial adhesion. The most effective anti-adhesive performance was observed in surfaces with parallel ridge patterns, which segmented the surface into isolated areas that limited bacterial interaction and hindered micro-colony formation, highlighting the importance of specific surface patterning in combating biofouling. [ABSTRACT FROM AUTHOR]

Embossing rolls are used in a variety of sectors to transfer surface textures to a product. Textures on the rolls are typically achieved by material-removal techniques, resulting in craters in the surface of the roll. The wear resistance of the surfaces is improved by additional coating technologies. A novel process offering improved surface design freedom and which negates the need for post-coating techniques is the embedding of micro-meter-sized ceramic particles in the surface of the roll. This can be achieved through micro-additive processing. This work presents and discusses experimental results of surface texturing through locally derived laser-induced melt pools in which ceramic particles are dissolved. This process is termed laser implantation, or laser dispersing. Using this technology, dome-shaped surface structures with significantly increased hardness compared to the bare steel can be achieved. Reported results in the literature focus on implantations with diameters ranging from 150 μ m to 400 μ m and heights ranging from 10 μ m to 30 μ m. However, features with smaller diameters and heights are desired for technology adoption to permit a wider range of surface roughness. This paper presents and discusses the experimental results of implantations with a diameter smaller than 150 µm, with heights between 1 μ m and 15 μ m. For that purpose, a Nd:YAG laser source (focal diameter 70 μ m, pulse durations from 3 to 15 ms, pulse power from 20 to 50 W average) was used to induce a melt pool driving the particle embedding. [ABSTRACT FROM AUTHOR]

The surface texture process was done with carbon dioxide laser on dual-phase steel (DP 1180). The effects of the parameters of the carbon dioxide laser on the contact angle, skewness and kurtosis values were investigated, and the laser parameters required for obtaining the highest contact angle, lowest skewness and highest kurtosis have been optimized by the Taguchi method. In addition, the effects of these parameters on contact angle, skewness and kurtosis were calculated. The most effective parameters were laser power with 33.03% for contact angle, overlap ratio with 52.48% for skewness and overlap ratio with 41.34% for kurtosis. In the optimization result to obtain the optimum values, contact angle, skewness and kurtosis were found as 145.45, 0.07 and 3.39, respectively. These results are better than those obtained in the experiments for all three quantities. Since the results of the confirmation experiments performed with the parameters suggested by the Taguchi method are quite close to the expected results, it can be said that the Taguchi method is a reliable method in such studies. The results are supported by main effect plots and regression equations. [ABSTRACT FROM AUTHOR]

This paper analyzes the tribological behavior of the Ti6Al4V ELI alloy subjected to laser texturization for medical purposes. Laser texturing enables one to observe specific patterns of the material surface at established depths. Microtexturing of the samples was performed using a 355 nm picosecond laser. The influence of the microtexturing process (depending on the process parameters) on the geometric parameters of the proposed laser texturing pattern was evaluated. Selected samples were subjected to tribological testing using the ball-on-plate technique in dry and lubricant-sliding methods (in Ringer solution). The wear properties were evaluated by comparing the coefficient friction, wear volumes, and wear ratio. A scanning electron microscope characterized the morphologies of the wear scar and the wear mechanism. The experimental results show that the surface texturing and the changes in microgrooves can reduce wear. The results indicate, that samples after laser texturing were characterized by 15% higher microhardness, compared to those in the initial state. It was found, a 26% reduction in friction coefficient and 29% in the wear volume compared to the smooth, untextured surface samples under lubricated conditions. The decrease in value of the coefficient friction and wear volume for the samples after the laser texturing process is an effect of synergistic of entrapped wear debris in micro-grooves and increased hardness for samples after laser textured. [ABSTRACT FROM AUTHOR]

Copyright of Diamond & Abrasives Engineering is the property of Zhengzhou Research Institute for Abrasives & Grinding and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The article is aimed at identifying the influence of laser texturing and subsequent coating with a hard, wear-resistant coating AlCrSiN (nACRo®) on selected tribological properties of the analyzed tool steels for cold work, produced by conventional and powder metallurgy. The substrate from each steel was heat treated to achieve optimal properties regarding the chemical composition and the method of production of the material. Böhler K100 and K390 Microclean® steels were used. These are highly alloyed tool steels used for various types of tools intended for cold work. The obtained results show that the coefficient of friction is increased by coating, but the wear rate is lower compared to the samples which were only textured. [ABSTRACT FROM AUTHOR]

Surface preparation is an important step in adhesive technology. A variety of abrasive, chemical, or concentrated energy source treatments are used. The effects of these treatments vary due to the variety of factors affecting the final strength of bonded joints. This paper presents the results of an experimental study conducted to determine the feasibility of using fiber laser surface treatments in place of technologically and environmentally cumbersome methods. The effect of surface modification was studied on three materials: aluminum EN AW-1050A and aluminum alloys EN AW-2024 and EN AW-5083. For comparison purposes, joints were made with sandblasted and laser-textured surfaces and those rolled as reference samples for the selected overlap variant, glued with epoxy adhesive. The joints were made with an overlap of 8, 10, 12.5, 14, and 16 mm, and these tests made it possible to demonstrate laser processing as a useful technique to reduce the size of the overlap and achieve even higher load-bearing capacity of the joint compared to sandblasting. A comparative analysis was also carried out for the failure force of the adhesive bond and the failure energy. The results show the efficiency and desirability of using lasers in bonding, allowing us to reduce harmful technologies and reduce the weight of the bonded structure. [ABSTRACT FROM AUTHOR]

Laser texturing enables site-selective tailoring of wetting characteristics of metallic surfaces, converting the surfaces into hydrophilic or hydrophobic ones. In this study, selective wettability transition of 6061 aluminum alloy (Al 6061) surface is demonstrated by using a nanosecond fiber laser. The conversion of initial wettability of pristine Al 6061 into a near-superhydrophobic surface is achieved through laser irradiation of an Al 6061 plate and the following low-temperature thermal annealing. The wettability change is studied by measuring the water contact angle, and a significant increase in the angle (approximately, from 63.9° of pristine Al 6061 to 146.8°) is observed. Furthermore, the laser-textured hydrophobic surface is transformed into a hydrophilic surface by irradiating the surface again with the laser beam, resulting in superwetting ability. These wettability transitions are site-selectively obtained by exploiting the capability of direct laser writing, showcasing a promising potential in various applications. [ABSTRACT FROM AUTHOR]

Zirconia-based dental implants are in direct contact with living tissues and any improvements in their bioactivity and adhesion to the tissues are highly welcome. In this study, different ratios of barium titanate (BT) were added to 3 mol% yttria-stabilized zirconia (3YSZ) through conventional sintering. The laser-texturing technique was also conducted to improve the biological performance of 3YSZ ceramics. The composition and the surface of the prepared composites were characterized by X-ray diffraction and scanning electron microscopy (SEM), respectively. The roughness and surface wettability of the composites were also measured. Furthermore, MC3T3-E1 pre-osteoblast cells were used for the in vitro experiments. Cell viability was evaluated using a commercial resazurin-based method. Morphology and cellular adhesion were observed using SEM. Based on the results, the laser texturing and the barium titanate content influenced the surface characteristics of the prepared composites. The laser-textured 3YSZ/7 mol% BT composites showed a lower water contact angle compared to the other samples, which indicated superior surface hydrophilicity. The cell viability and cell adhesion of 3YSZ/BT composites increased with the rise in the barium titanate content and laser power. An elongated cell morphology and apatite nucleation were also observed by the BT content. Overall, the laser-treated 3YSZ/5 and 7 mol% BT composites may be promising candidates in hard tissue repair due to their good cell response. [ABSTRACT FROM AUTHOR]

The rapid advancement of engineering systems has spurred the search for innovative thermal management solutions. Boiling, as a phase‐change heat transfer method, has shown promise in heat dissipation, but non‐functionalized surfaces struggle with increasing cooling demands. To improve heat dissipation efficiency across different heat loads, functionalized surfaces with tailored wettability have been proposed. Separately, superhydrophilic and superhydrophobic surfaces each offer benefits and drawbacks in boiling applications but combining them on a single "biphilic" surface simultaneously harnesses their advantages. In this study, laser‐functionalized copper surfaces with spatially tailored wettability are developed by combining two‐step laser texturing with a self‐assembled monolayer coating, while focus is placed on the impact of the size and pitch of superhydrophobic spots. The developed functionalized surfaces exhibit exceptional boiling performance with heat transfer coefficients up to 299 kW m−2 K−1, a 434% enhancement over untreated surfaces. Optimal ratios of superhydrophilic and superhydrophobic areas and optimal spot pitch are identified. Additionally, varying behavior at different heat flux levels is observed, emphasizing the importance of considering thermal loads when determining the optimal surface pattern. This advancement in performance, along with the rapid and cost‐effective functionalization process, represents a significant breakthrough for enhanced thermal management applications. [ABSTRACT FROM AUTHOR]

Glass surfaces tend to be hydrophilic when exposed to water resulting in a low water contact angle and high adhesion. Fabrication on a glass surface with low water adhesion can minimize the droplet's adhesion conduct self-cleaning, and improve the cleanliness of the glass surface. This paper presents surface texturing of the soda-lime glass surface by laser processing three different patterns to improve water contact angle with low water adhesion on the modified glass surface. A design experiment method was developed to determine the effects of laser parameters on the glass surfaces. The laser parameters used are laser power between 0.45 and 1.05W and scanning speeds of 210, 420, and 600 mm/min. The effects of laser parameters on surface morphology, water contact angle measurement, and average surface roughness, Ra were investigated. The characterization was conducted for surface morphology, two-dimensional surface roughness profile, and water contact angle. The results show that the highest water contact angle obtained after laser texturing is up to 125.29° compared to the as-received surface with a contact angle of 32.35°. The highest water contact angle resulted from 420 mm/min scanning speed and 0.45 W of laser power, responding to the surface with a minimum range of Rax and Ray of 0.96 and 1.5 µm. These findings are significant for designing surface modification of self-cleaning glass surface applications like the automotive windscreens, and window panels for high-rise buildings. [ABSTRACT FROM AUTHOR]

Prior studies have evidenced the potential for enhancing boiling heat transfer through modifications of surface or fluid properties. The deployment of nanofluids in pool boiling systems is challenging due to the deposition of nanoparticles on structured surfaces, which may result in performance deterioration. This study addresses the use of TiO2–water nanofluids (mass concentrations of 0.001 wt.% and 0.1 wt.%) in pool boiling heat transfer and concurrent mitigation of nanoparticle deposition on superhydrophobic laser-textured copper surfaces. Samples, modified through nanosecond laser texturing, were subjected to boiling in an as-prepared superhydrophilic (SHPI) state and in a superhydrophobic state (SHPO) following hydrophobization with a self-assembled monolayer of fluorinated silane. The boiling performance assessment involved five consecutive boiling curve runs under saturated conditions at atmospheric pressure. Results on superhydrophilic surfaces reveal that the use of nanofluids always led to a deterioration of the heat transfer coefficient (up to 90%) compared to pure water due to high nanoparticle deposition. The latter was largely mitigated on superhydrophobic surfaces, yet their performance was still inferior to that of the same surface in water. On the other hand, CHF values of 1209 kW m−2 and 1462 kW m−2 were recorded at 0.1 wt.% concentration on both superhydrophobic and superhydrophilic surfaces, respectively, representing a slight enhancement of 16% and 27% compared to the results obtained on their counterparts investigated in water. [ABSTRACT FROM AUTHOR]

Skin-pass rolls are used for setting the final sheet thickness and surface texture. For sheet metal that is produced for forming, textured skin-pass rolls featuring a high-low structure are used in order to improve the formability and paint adhesion of the sheet. In this paper, new textures for skin-pass rolls generated by high-speed laser melt injection (HSLMI) are presented and characterized. Furthermore, it is studied how the texture of the roll is transferred to steel and aluminum sheets. With HSLMI, metal matrix composite (MMC) layers featuring spherical fused tungsten carbide (SFTC) particles with a high hardness could be produced on skin-pass rolls. For generating an increased high-low structure, laser ablation and electrolytic etching were carried out after HSLMI and grinding of the rolls. An analysis of the topography showed that different protruding heights between SFTC particles and matrix can be set. The textures generated by laser ablation showed a topography featuring two homogeneous height levels, whereas a texture with spherically shaped particles could be generated by electrolytic etching. Furthermore, it was found that all textures were transferred from the roll to both steel and aluminum sheets. The transfer of the textures mainly depended on the protruding height of the SFTC particles and the SFTC particle content of the roll. [ABSTRACT FROM AUTHOR]

The adoption of lightweight materials in engineering applications has become more popular over recent years, with adhesives replacing traditional joining methods such as bolts and rivets. Adhesion science and related technologies are arising as cleaner options for sustainable production in modern industry, with adhesive-bonded joints increasingly being used as design solutions in complex products and assemblies. However, the use of structural adhesives has several significant drawbacks, most of which are related to environmental impact, linked to the nature of the adhesive substance, as well as product disassembly/disposal deriving from the fact that adhesive joints are usually irreversible. Within this context, the goal of this paper is to study adhesive joints in mechanical assemblies from a life cycle perspective, offering more comprehensive analysis tools and assembly solutions suitable for industries such as automotive, aerospace, and assembly/packaging machinery. A methodological framework for the comprehensive characterization of bonded joints using effective surface activation techniques has been created and tested. The first phase encompasses the production of samples for mechanical testing under static and fatigue loading conditions. The second includes the characterization of inputs/outputs (life cycle inventory—LCI) for life cycle assessment (LCA) of mechanical assemblies employing adhesive joints and innovative surface activation techniques. The final phase provides a set of eco-design actions based on a critical analysis of the obtained results. The outcomes demonstrate how it is possible to achieve optimal adhesive-bonded joint properties under specific working conditions (e.g., static or fatigue loading) while maintaining a low environmental load using novel surface pre-treatments such as laser and plasma technologies. These outcomes are supported by a case-study in which adhesive joints are applied to the mechanical assembly of a bottle gripper for a food packaging machine. The adoption of eco-design rules in adhesive joint applications will help designers in the development of suitable solutions for lightweight applications from a complete life cycle perspective. [ABSTRACT FROM AUTHOR]

Rendering transparent materials extreme wettability, for example, superhydrophobicity or superhydrophilicity, has received considerable attention during the past decades. While fabrication of superhydrophobic glass with high processing efficiency and low production cost has always been a challenge. In this work, a laser‐based surface functionalization process that combines ultraviolet (UV) nanosecond laser texturing and silicone oil‐assisted heat treatment was employed to render glass superhydrophobicity with high process throughput. The wettability transition is attributed to the combined effects of laser texturing that induces hierarchical surface micro/nanostructures and silicone oil‐assisted heat treatment that alters surface chemistry and lowers surface energy. The surface transmittance of the laser‐based surface functionalized glass samples in the visible spectrum was experimentally measured and analyzed. The laser‐based surface functionalized glass sample also exhibited long‐term stability in air, mechanical robustness and good self‐cleaning property. More importantly, the developed process shows both high process efficiency and cost effectiveness and has potential for applications where superhydrophobic glass is required. [ABSTRACT FROM AUTHOR]

In this work, zinc oxide–based piezoelectric nanogenerator (PENG) over the flexible Kapton polyimide (PI) substrate is developed. The device performance is improved by laser texturing of PI substrate, which increases the effective surface area of PI and adhesivity of ZnO thin film with PI substrate to improve the reliability and life span of the device. The untextured PI‐based PENG generates a peak‐to‐peak output voltage, current, and power of 6 V, 420 nA, 2.42 μW, respectively, which increases to 15.8 V, 790 nA, and 12.51 μW, respectively, on using textured PI obtained by 60% laser spot overlap. On further increasing the laser spot overlap to 80%, the peak‐to‐peak output voltage, current, and power improve to 22.2 V, 1210 nA, and 26.88 μW, respectively. Therefore, as compared to the untextured‐PI‐based PENG, laser‐textured‐PI‐based PENG is a promising candidate for energy‐harvesting applications. [ABSTRACT FROM AUTHOR]

This study investigates the use of a CuBr vapor nanosecond laser with a 510 nm/578.2 nm wavelength for the surface treatment of 1050 aluminum and 2219 aluminum alloys. Laser-induced periodic surface structuring was used to optimize processing parameters to achieve hydrophobic and hydrophilic properties on the surface. The wetting properties were measured and the roughness results (Ra, Rz, Rq) evaluated. Prior to and after laser treatment, surface wetting and roughness changes were investigated. The wetting study showed that the maximum contact angle between a droplet of deionized water and the treated surface can be reached between more than 140 degrees and less than 10 degrees, which, respectively, is a superhydrophobic and superhydrophilic surface. Compared with the untreated surface, wetting increased by more than 2 times and decreased by more than 8 times. Overall, experiments show the dependence of wetting properties on laser input parameters such as scan speed and scan line distance with different delivered energy amounts. This study demonstrates the possibility of laser parameter optimizations which do not require auxiliary gases and additional processing of the resulting surfaces to obtain different wetting properties on the surface. The findings described in this article suggest that the CuBr laser surface treatment method is a promising method for industrial applications where surfaces with special wetting and roughness properties are required, for example, the laser marking of the serial number of parts used in wet environments such as aerospace, shipbuilding, and defense industries. [ABSTRACT FROM AUTHOR]

Si is a highly promising anode material due to its superior theoretical capacity of up to 3579 mAh/g. However, it is worth noting that Si anodes experience significant volume expansion (>300%) during charging and discharging. Due to the weak adhesion between the anode coating and the smooth Cu foil current collector, the volume-expanded Si anode easily peels off, thus damaging anode cycling performance. In the present study, a femtosecond laser with a wavelength of 515 nm is used to texture Cu foils with a hierarchical microstructure and nanostructure. The peeling and cracking phenomenon in the Si anode are successfully reduced, demonstrating that volume expansion is effectively mitigated, which is attributed to the high specific surface area of the nanostructure and the protection of the deep-ablated microgrooves. Moreover, the hierarchical structure reduces interfacial resistance to promote electron transfer. The Si anode achieves improved cycling stability and rate capability, and the influence of structural features on the aforementioned performance is studied. The Si anode on the 20 μm-thick Cu current collector with a groove density of 75% and a depth of 15 μm exhibits a capacity of 1182 mAh/g after 300 cycles at 1 C and shows a high-rate capacity of 684 mAh/g at 3 C. [ABSTRACT FROM AUTHOR]

Superhydrophobic surfaces are highly desirable due to their remarkable water-repellent behavior. Laser texturing with subsequent low surface energy modification is a versatile strategy for creating such surfaces. In this study, via synergistic laser texturing and low temperature annealing, superhydrophobicity was first attempted to be achieved on the FeCoCrMnNi surface. By optimizing the laser parameters, the arrays with large depth-to-width ratios were constructed. Subsequently, by annealing at a low temperature, the transition process from superhydrophilicity to superhydrophobicity was successfully achieved on the FeCoCrMnNi surface. The effects of the hatching interval on the wettability were investigated, and the mechanism of wettability transition for FeCoCrMnNi was discussed. According to the experimental results and analysis, the textured surfaces exhibited excellent superhydrophobicity at different hatching intervals and a maximum contact angle of 165° was obtained. Furthermore, the created superhydrophobic surfaces possessed good liquid capture and self-cleaning capabilities and enabled magnification for optical imaging. The wettability transition after low temperature annealing was attributed to the absorption of airborne organic compounds. This study provides an efficient, clean, and versatile strategy to achieve superhydrophobicity of the FeCoCrMnNi surface by laser processing. [ABSTRACT FROM AUTHOR]

Shallow Hilbert curve patterns with easily programmable texture density were selected for laser texturing of stainless steel substrates. Two different texture path segment lengths (12 and 24 µm) and four different laser power percentages (5%, 10%, 15%, and 20%) were investigated. The textured and smooth substrates were coated with thin polydopamine/polytetrafluoroethylene (PDA/PTFE) coatings for tribological property assessment. The effects of texture density (texture area coverage) and laser power on the durability and friction of the coated surfaces were studied. Laser texturing the substrates improved the coating durability up to 25 times, reduced the friction coefficient, and prevented coating global delamination. The textures fabricated with a laser power of 15% and a texture path segment length of 12 µm yielded the best coating durability. The textures provided the interlocking for the PTFE coating and thus prevented its global delamination. Furthermore, the PTFE inside the texture grooves replenished the solid lubricant worn away in the wear track and prolonged the coating wear life. [ABSTRACT FROM AUTHOR]

This paper presents the main texturing methods of metal surfaces, from the perspective of existing studies. This article explores different surface texturing methods and techniques, with an emphasis on using them to improve mechanical and tribological properties. Through a comprehensive analysis, the article addresses traditional texturing techniques as well as emerging technologies. In addition, the benefits and limitations of each method are highlighted, and recent articles in the field are reviewed to provide a complete picture of current developments in surface texturing. [ABSTRACT FROM AUTHOR]

According to the literature data graphene oxide cannot be easily used as an anti-corrosion barrier on metals and alloys, especially on carbon steel. This article shows that the oxidised form of graphene can improve the electrochemical corrosion parameters of carbon steel, if necessary modifications on the surface structure and wettability of steel are made prior to the coating step. In this study, the effects of surface roughness and hydrophilicity of carbon steel on the anti-corrosion performance of the electrophoretically deposited graphene oxide were investigated by potentiodynamic polarization and electrochemical impedance spectroscopy. The results showed that increasing the roughness and hydrophilicity of the bare steel surface promotes the mechanical interlocking/adhesion between the graphene oxide and steel and this improves the protective performance of the deposited graphene oxide barrier on steel. [ABSTRACT FROM AUTHOR]

The aim of the study was to evaluate the effects of laser texturing of coated textile materials on their cut resistance. The investigated material was an aramid knitted fabric coated with a polymer layer made of an acrylic-styrene dispersion functionalized with particles of silicon carbide (SiC). The distribution of SiC particles in the coating microstructure was assessed on the basis of microscopic observations (scanning electron microscopy). The coating was laser textured, and then the cut resistance of the assembly was determined using a rectangular blade. The findings showed that laser texturing improved the cut resistance of the tested materials, causing a fourfold increase in that parameter as compared to non-modified textile materials. This fact may improve the safety of workers wearing protective gloves in terms of cut protection. [ABSTRACT FROM AUTHOR]

Chemical modification is usually utilized for preparing superhydrophobic SiC surfaces, which has the problems of long processing time, high environmental contamination risk, and high cost. To enhance the condensation heat transfer efficiency of SiC, the superhydrophobic SiC surface was fabricated through laser texturing and heat treatment. In this study, the SiC surface was processed by laser texturing with a nanosecond laser, followed by heat treatment. Surface microstructures and compositions were investigated with SEM and XPS, and the heat transfer coefficient of the superhydrophobic SiC surface was tested. The results indicated that the laser-textured SiC surface had a super hydrophilic contact angle of 0°; after heat treatment, SiC ceramic became superhydrophobic (surface contact angle reaches 164°) because organic contamination on the original SiC surface could be cleaned by using laser texturing, which caused a chemical reaction and the formation of SiO2 on the surface. Moreover, the distribution of relatively low-energy SiOX was formed after heat treatment; then, SiC ceramic became superhydrophobic. Due to the formation of nanoscale sheet-like protrusion structures by heat treatment, the SiC superhydrophobic surface exhibited typical dropwise condensation, and the condensation heat transfer coefficient reached 331.8 W/(m2·K), which was 2.3 times higher than that of the original surface. [ABSTRACT FROM AUTHOR]

The surface of the commercial CoCr28Mo alloy was textured using a 20W pulsed fiber laser according to different beam scan strategies. Surface roughness and drop contact angle measurements made on the textured surface were used to evaluate the effects of process parameters. The surface topography was highly affected by both scan direction and beam overlaps named pulse-to-pulse overlap and scan overlap. As the beam overlap ratio increased, the amount of heat transferred to the unit area also increased, which caused more metal to evaporate in the interaction zone and form a more considerable amount of molten and re-solidified metal layer, resulting in a chaotic texture formation on the surface. The mean surface roughness values of textured surfaces for eighteen test samples ranged from 1 to 7 μm. These surface roughness values were in the micro-scale roughness value range. According to the results of the drop contact angles, the surface topography significantly changed the wettability. The test results were also analyzed by the Taguchi method considering signal-to-noise ratios and evaluated by analysis of variance. Considering the highest S/N values for each parameter, the optimum parameters combination for the laser engraving process was 45°/-45° for scan direction, 70 % for power, 1000 mm/s for scan speed, 50 kHz for frequency, 0.01 mm for hatch distance, and 75 ns for pulse duration. [ABSTRACT FROM AUTHOR]

A hybrid approach based on laser texturing and surface coating for the combined modification of surface topography and chemistry has been proposed to provide a versatile approach for the development of functional surfaces. The experimental procedure comprised nanosecond pulsed laser texturing of AISI 304 stainless steel substrates followed by the deposition of thin (<1 µm) coatings with two different technologies, sol–gel deposition and PE-CVD, with the aim of independently modifying the surface topography and chemical composition. Laser texturing with different scanning strategies achieved a variety of surface morphologies with an arithmetic mean height (Sa) in the range 0.2–6.4 µm. Coatings were then deposited on laser-textured substrates to quantify the deposition effectiveness and the influence of the coating type and parameters on the resulting surface topography and chemistry. Sol–gel deposition was found to be more effective with a polymeric interlayer, improving adhesion between the coating and the textured surface; however, this also led to an increase in Sa of approximately 0.5 µm. Conversely, PE-CVD was effective in modifying the surface chemistry while inducing no measurable differences in surface morphology, effectively decoupling the texturing and coating processes. Analysis of the surface chemistry showed a higher concentration of silicon for PE-CVD than sol–gel deposition and therefore a more pronounced effect on the surface chemical composition. [ABSTRACT FROM AUTHOR]

Laser texturing offers a substantial advantage over traditional texturization in design, quality and flexibility. This study investigates nanosecond fiber laser textured surfaces with different patterns (Circle, Pyramid and Polygon) on optical characteristics like absorption and reflection. It exhibits a lengthy absorption path (200-900 nm) and a higher rough surface by surface changes, a roughly 20% reduction in incident light reflectance that enable higher light-trapping employed in solar cells. The surface features like surface morphology and surface roughness of the micro-textured silicon surface were examined by a three-dimensional profilometer, scanning electron microscope (SEM) and Atomic force microscopy (AFM) to determine the effectiveness of the process. Surface roughness Ra increased after texturing from 1.006 to 11.09 µm. The SEM micrographs recognize overlapping patterns that are deep enough to trap light, while reflection tests reveal that the specimens have low reflectivity. AFM images of the micro-textured surface are analyzed to reveal the roughness, height variations, fractal dimension, etc. After laser irradiation, crystallographic structure and crystallinity change were examined using XRD, Micro-Raman spectroscopy. [ABSTRACT FROM AUTHOR]

Light-trapping structures formed on surfaces of various materials have attracted much attention in recent years due to their important role in many applications of science and technology. This article discusses various methods for manufacturing light-trapping "black" silicon, namely laser, chemical and hybrid chemical/laser ones. In addition to the widely explored laser texturing and chemical etching methods, we develop a hybrid chemical/laser texturing method, consisting in laser post-texturing of pyramidal structures obtained after chemical etching. After laser treatments the surface morphology was represented by a chaotic relief of microcones, while after chemical treatment it acquired a chaotic pyramidal relief. Moreover, laser texturing of preliminarily chemically microtextured silicon wafers is shown to take five-fold less time compared to bare flat silicon. In this case, the chemically/laser-treated samples exhibit average total reflectance in the spectral range of 250–1100 nm lower by 7–10% than after the purely chemical treatment. [ABSTRACT FROM AUTHOR]

In this study, a scatterometry-based monitoring system designed for tracking the quality and reproducibility of laser-textured surfaces in industrial environments was validated in off-line and real-time modes. To this end, a stainless steel plate was structured by direct laser interference patterning (DLIP) following a set of conditions with artificial patterning errors. Namely, fluctuations of the DLIP process parameters such as laser fluence, spatial period, and focus position are introduced, and also, two patterning strategies are implemented, whereby pulses are deliberately not fired at both deterministic and random positions. The detection limits of the system were determined by recording the intensities of the zero, first, and second diffraction order using a charge-coupled device (CCD) camera. As supported by topographical measurements, the system can accurately calculate spatial periods with a resolution of at least 100 nm. In addition, focus shifts of 70 µm from the optimum focus position can be detected, and missing patterned lines with a minimum width of 28 µm can be identified. The validation of this compact characterization unit represents a step forward for its implementation as an in-line monitoring tool for industrial laser-based micropatterning. [ABSTRACT FROM AUTHOR]

In times of societal development, sustainability has become a major concern for many manufacturers in the metal industries. In this context, surface texturing of cutting tools offers a promising approach in terms of reducing energy consumption and material waste. In this work, direct laser interference patterning is utilized for producing periodic line-like structures with spatial periods of 2.0 µm and 5.5 µm on rake-flank faces of cemented tungsten carbide cutting inserts. Structure depths up to 1.75 µm are reached by controlling the applied number of laser pulses. Turning experiments under lubricated conditions carried out on Al 6061 T6 parts with textured and untreated tools are performed to determine their tribological performances. The used textured cutting tools can effectively decrease machining forces up to 17% due to the corresponding improvement in frictional behavior at the tool/chip interface. Furthermore, the laser-processed tools produce thinner chips and decrease the surface roughness by 31% of the aluminum work piece. [ABSTRACT FROM AUTHOR]

Among metallic biomaterials, near-equiatomic NiTi is one of the most promising intermetallic system applicable for biomedical applications, thanks to its high biocompatibility and unique superelasticity (or pseudoelasticity), offering a complete recoverable strain up to 8%. In the prospective uses for bio-devices, the surface processing of NiTi medical components plays a fundamental role for guaranteeing both a Ti oxide passivizing layer for avoiding Ni ion release into the human body and surface morphology for controlling the cell proliferation. Mechanical polishing, thermal, chemical or electro-chemical treatments are typically performed for surface modifications. Recently, laser texturing has been successfully applied for different materials, included NiTi shape memory alloys, and also for tuning the surface properties, such as wettability. In the present work, ultrashort laser surface modification was carried out, through the use of a femtosecond laser, for the surface texturing of commercial superelastic NiTi plates. The main goal is to investigate the correlation among morphology, chemical composition and wettability with the principal process parameters, such as average power and scanning velocity in high power ultrashort laser texturing. Laser patterned surfaces were characterized by means of scanning electron microscopy, 3D-profilometry, XPS analysis and wetting measurements. After the laser treatments, both surface morphology and Ni/Ti ratio were largely modified from the initial surface, depending on the adopted process parameters. The wettability of the laser textured surfaces can be also varied with respect to the initial surface, due to the roughness values and grooves induced by the laser beam scans. The laser texturing process induced a combination between micro and nano structures, depending on the input energy. In details, the surfaces were tuned to lower roughness values (from 0.4 μm to 0.3 μm) with a laser power of 1 W, while it was increased up to 0.65 μm with a laser power of 13 W. The laser surface modification promoted a change of the contact angle from 70° of the untreated condition up to 135° to the surface laser treated with a power of 13 W. [ABSTRACT FROM AUTHOR]

Polycrystalline boron-doped diamond (BDD) films were surface nanotextured by femtosecond pulsed laser irradiation (100 fs duration, 800 nm wavelength, 1.44 J cm−2 single pulse fluence) to analyse the evolution of induced alterations on the surface morphology and structural properties. The aim was to identify the occurrence of laser-induced periodic surface structures (LIPSS) as a function of the number of pulses released on the unit area. Micro-Raman spectroscopy pointed out an increase in the graphite surface content of the films following the laser irradiation due to the formation of ordered carbon sites with respect to the pristine sample. SEM and AFM surface morphology studies allowed the determination of two different types of surface patterning: narrow but highly irregular ripples without a definite spatial periodicity or long-range order for irradiations with relatively low accumulated fluences (<14.4 J cm−2) and coarse but highly regular LIPSS with a spatial periodicity of approximately 630 nm ± 30 nm for higher fluences up to 230.4 J cm−2. [ABSTRACT FROM AUTHOR]

Abstract—The present work demonstrates the possibility of fabrication of superhydrophobic (SHP) coatings on the surface of technically pure magnesium using laser texturing followed by modification in organic acid solutions. A comparison of the three methods of preliminary preparation showed that, by means of a laser marker, it was possible to create a greater surface roughness than at sandpapering or etching. In addition, such a surface would be uniform, in contrary to that after etching. Of the studied compounds, octadecylphosphonic acid (ODPA) is the best hydrophobizer. To attain the superhydrophobic properties of Mg90 by means of it, an ethanol solution of a lower concentration than stearic (SA) or oleic (OA) acids (1 and 10 mmol, respectively) is necessary. The results of corrosion tests have shown that the SHP coatings of ODPA provide longer-lasting protection than OA and SA films. [ABSTRACT FROM AUTHOR]

Laser processing of dental implant surfaces is becoming a more widespread replacement for classical techniques due to its undeniable advantages, including control of oxide formation and structure and surface relief at the microscale. Thus, using a laser, we created several biomimetic topographies of various shapes on the surface of titanium screw-shaped implants to research their success and survival rates. A distinctive feature of the topographies is the presence of "µ-rooms", which are special spaces created by the depressions and elevations and are analogous to the µ-sized room in which the osteocyte will potentially live. We conducted the comparable in vivo study using dental implants with continuous (G-topography with µ-canals), discrete (S-topography with μ-cavities), and irregular (I-topography) laser-induced topographies. A histological analysis performed with the statistical method (with p-value less than 0.05) was conducted, which showed that G-topography had the highest BIC parameter and contained the highest number of mature osteocytes, indicating the best secondary stability and osseointegration. [ABSTRACT FROM AUTHOR]

Increased cooling requirements of many compact systems involving high heat fluxes demand the development of high-performance cooling techniques including immersion cooling utilizing pool boiling. This study presents the functionalization of copper surfaces to create interfaces for enhanced pool boiling heat transfer. Three types of surface structures including a crosshatch pattern, shallow channels and deep channels were developed using nanosecond laser texturing to modify the surface micro- and nanomorphology. Each type of surface structure was tested in the as-prepared superhydrophilic state and superhydrophobic state following hydrophobization, achieved through the application of a nanoscale self-assembled monolayer of a fluorinated silane. Boiling performance evaluation was conducted through three consecutive runs under saturated conditions at atmospheric pressure utilizing water as the coolant. All functionalized surfaces exhibited enhanced boiling heat transfer performance in comparison with an untreated reference. The highest critical heat flux of 1697 kW m−2 was achieved on the hydrophobized surface with shallow channels. The highest heat transfer coefficient of 291.4 kW m−2 K−1 was recorded on the hydrophobized surface with deep channels at CHF incipience, which represents a 775% enhancement over the highest values recorded on the untreated reference. Surface microstructure was identified as the key reason for enhanced heat transfer parameters. Despite large differences in surface wettability, hydrophobized surfaces exhibited comparable (or even higher) CHF values in comparison with their hydrophilic counterparts, which are traditionally considered as more favorable for achieving high CHF values. A significant reduction in bubble departure diameter was observed on the hydrophobized surface with deep channels and is attributed to effective vapor entrapment, which is pointed out as a major contributing reason behind the observed extreme boiling heat transfer performance. [ABSTRACT FROM AUTHOR]

Surface textures such as laser-induced periodic surface structures (LIPSS) are of great interest to obtain industrial nanopatterns. In this work, plain uncoated 1.2344 steel with and without Chromium Nitride (CrN) and CrN plus diamond-like carbon (DLC) coatings were used in experiments. The laser texturing variables studied were the laser speed (3000–4000 mm/s) and the distance between laser lines (1–10 microns). These structures were characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM) to obtain an overview of the roughness and to analyze the heights of the obtained structures. A two-dimension fast Fourier transform (2D-FFT) of the SEM images and its characteristic frequencies was used to assess the periodicity of the textured surfaces and thus quantify the far-range order. The speed of laser depth ablation is related to the laser energy density for each coating and textures are qualified using the FFT approach. [ABSTRACT FROM AUTHOR]

Metal substrates are widely used in engineering production. However, material life reduction and economic loss due to chemical and electrochemical corrosion are a major problem facing people. Electrochemical corrosion is the main corrosion mode of metals, such as seawater corrosion. It is found that the superhydrophobic surface treated by laser texturing plays an important role in the corrosion resistance of the substrate, with the laser texturing process and post-treatment affecting the corrosion resistance. The corrosion resistance is positively correlated with the superhydrophobic property of the surface. For the mechanism of corrosion resistance, this paper summarizes the effect of micro-nano structure, surface-modified coating, oxidation layer or new product layer, surface inhomogeneity, crystal structure, and slippery surface on corrosion resistance. Superhydrophobic surface and slippery surface are two common types of bioinspired, special wetting surfaces. In order to prepare better superhydrophobic and corrosion-resistant surfaces, this paper summarizes the selection and optimization of laser parameters, surface structure, processing media, and post-treatment from the point of view of mechanism and law. In addition, after summarizing the corrosion resistance mechanism, this paper introduces a series of characterization experiments that can measure the corrosion resistance, providing a reference for preparation and evaluation of the surface. [ABSTRACT FROM AUTHOR]

Laser texturing of surfaces may provide specific functionality, such as altering hydrophobicity, changing optical properties, or reducing friction and wear. For the latter, surfaces of parts are often coated with protective and/or solid lubricant coating, and texturing may further improve the tribological properties in both dry or lubricated sliding. New laser technologies, such as the direct laser writing (DLW) method using a femtosecond laser, allow the production of extremely precise textures directly into the coating. Here, we describe a method of preparing ultra-precise textures into diamond-like carbon (DLC) coatings on a large area. The textured topography was assessed by 3D laser scanning microscope, which confirmed the repeatability of fs laser processing. Raman spectroscopy mapping, SEM, and XPS were combined to investigate the effect of laser processing on DLC coating in terms of oxidation or structural changes. Traditional process (i.e., coating textured surface) often results in coating adhesion/cohesion failure due to deposition of sharp edges produced by texturing, whereas our approach eliminates this issue. Even complex textures inside the coating are fabricated with a fast speed of 10 s per mm2 and a high precision in texture depth (tens of nanometers), unlocking many application fields in tribology or microfluidics. [ABSTRACT FROM AUTHOR]

An asymmetric friction principle is newly proposed for the design of inertial impact piezoelectric actuators. There are two ways to achieve asymmetric frictions: either by tuning the positive pressure or by tuning the friction coefficient. Compared with tuning the positive pressure by an asymmetric structure, the structural parameters can be reduced by employing a symmetric structure and tuning the friction coefficient. In this study, an asymmetric friction inertial impact actuator was developed using a symmetric compliant mechanism (SCM), and the asymmetric frictions were realized by laser texturing of the driving feet at one end of the SCM. Four kinds of microstructures were initially fabricated on the driving feet, and their friction properties were experimentally tested. Accordingly, two kinds of microstructures, namely Ta and Tb microstructures, were selected. Output characteristics of the actuator with these two microstructures were measured and comparatively analyzed. The experimental results indicate that the actuator could achieve stable step motion, and the output characteristics were affected by the fabricated microstructure, as it determined the friction coefficient. The actuator with the Tb microstructure achieved a maximum speed of 2.523 mm/s, a resolution of 188 nm, a vertical loading capacity of 2 N and a horizontal loading capacity of 0.6 N, whereas the actuator with the Ta microstructure had a higher resolution of 74 nm. This study provides a novel idea for the design of asymmetric friction inertial impact actuators by tuning the friction coefficient. [ABSTRACT FROM AUTHOR]

There are many factors influencing the accuracy of surface topography measurement results: one of them is the vibrations caused by the high-frequency noise occurrence. It is extremely difficult to extract results defined as noise from the real measured data, especially the application of various methods requiring skilled users and, additionally, the improper use of software may cause errors in the data processing. Accordingly, various thresholding methods for the minimization of errors in the raw surface topography data processing were proposed and compared with commonly used (available in the commercial software) techniques. Applied procedures were used for the minimization of errors in the surface topography parameters (from ISO 25178 standard) calculation after the removal and reduction, respectively, of the high-frequency noise (S-filter). Methods were applied for analysis of the laser-textured surfaces with a comparison of many regular methods, proposed previously in the commercial measuring equipment. It was found that the application of commonly used algorithms can be suitable for the processing of the measured data when selected procedures are provided. Moreover, errors in both the measurement process and the data processing can be reduced when thresholding methods support regular algorithms and procedures. From applied, commonly used methods (regular Gaussian regression filter, robust Gaussian regression filter, spline filter and fast Fourier transform filter), the most encouraging results were obtained for high-frequency noise reduction in laser-textured details when the fast Fourier transform filter was supported by a thresholding approach. [ABSTRACT FROM AUTHOR]

A high volume of wastewater is drained out every year from agriculture and industrial operations. In the present study, Microbial Fuel Cells (MFC) are used to generate electricity from sugarcane wastewater using titanium as an anode material. Besides, three different laser texturing such as linear pattern (LP), sinusoidal pattern (SP), and waviness pattern (WP) are created on titanium surface to enhance the electricity production and has been compared with the un-textured surface (UTS). In addition, water contact angle and roughness are measured on un-textured surface, LP, SP, and WP surfaces which are 60°, 45°, 34°, 20° and 2.9 μm, 10.7 μm, 15.9 μm, and 19.0 μm, respectively. Results show that laser textured surfaces exhibit a higher power density than the un-textured surface. The improvement in power density is 2–3.5 times that in un-textured surfaces. The outcome of this study indicates that laser textured microbial fuel cells can be considered as an efficient technique for generating electricity from the wastewater and also this could be considered as a new technique to offset wastewater treatment plant operating costs. [ABSTRACT FROM AUTHOR]

In this work the influence of picosecond laser (ps) irradiation (PLI) on the properties of black Cr electrodeposited on an SS substrate has been investigated. XPS has shown that black Cr treatment by PLI changes the concentrations of elements on the black Cr coating surface. Furthermore, it diminishes the quantity of CrN compound, while increasing the quantity of metallic chromium (Cro). Full reflectance (RD) of black Cr after treatment with PLI and before treatment in the visible region (300–800 nm) were quite close. Thermal tests at a temperature of 200 oC showed that the adhesion between black Cr treated with PLI and SS is better than that of black chromium not treated with PLI. Thus, such a black Cr absorber may be used in solar water heaters. [ABSTRACT FROM AUTHOR]

Over the past decade, interest has increased in controlling the wettability of metal surfaces with various liquids. In particular, the use of hydrophobic functional surfaces improves the efficiency and reliability of thermal power plants and systems operating in various areas of life. One of the most promising ways to achieve a hydrophobic state of structural materials is surface modification using laser equipment: laser ablation. As a result of exposure to laser radiation, melting, evaporation and recrystallization of the surface layer of the metal occur. By varying the parameters of exposure to laser radiation, it is possible to form a relief with specified geometric characteristics on a metal surface. The creation of hydrophobic metal surfaces using laser equipment includes the following steps: choosing the type of laser source, determining the radiation parameters and the trajectory of the laser beam over the surface, preparing the initial surface, forming the relief, and reducing the surface energy after laser ablation. This paper presents an overview of the results of research on the creation of hydrophobic metal surfaces based on the formation of a structured relief. In most studies, a relief was formed on the surface of metal samples in the form of equidistant lines, a grid, or had no pronounced structure (irregular structure). It has been established that the hydrophobic state of a metal surface with the highest contact angles (more than 150°) is achieved by laser texturing of the relief in the form of equidistant lines or a grid with a step not exceeding 100 μm. The maximum contact angle (approximately 179°) was obtained by forming a relief in the form of a grid with mutually perpendicular lines equidistant at 15 and 20 µm. [ABSTRACT FROM AUTHOR]

Biodegradable metallic alloys are promising materials for the development of temporary medical implants, including cardiovascular and orthopedic devices. The present work explores the surface modification of a biodegradable Fe–20Mn alloy by means of ultrashort laser texturing and the correlation between the laser‐induced surface morphology and the degradation behavior. In detail, the effect of different processing parameters on surface morphology is explored and compared with the unprocessed surface. It is found that laser texturing can tune the degradation rate, selectively inducing positive (+29%) or negative (−31%) change with respect to the untreated surface. [ABSTRACT FROM AUTHOR]

The paper presents certain problems related to the lubrication of textured surfaces. It was noted that for a specific load, the lubrication effectiveness will depend on the shape, size and mutual distribution of the texture's elements. Proposals for determining the lubrication irregularity parameters were presented for textures with a rectangular mesh and round recesses. The experimental part presents the laser texturing methodology, tribological testing methodology and preliminary test results where the significant role of the relationship between the trajectory of motion and the texture mesh was demonstrated. [ABSTRACT FROM AUTHOR]

MC-Si is the most widely used material for making solar PV cells. In spite of the considerable research on improving the conversion efficiency of MC-Si solar PV cells still it remains well within the range of 15-20%. Optical reflectance being the major loss of incident solar energy, efforts are being made to reduce the optical reflectance of solar cell surfaces. Among the several methods proposed, creation of well-defined surface topography on the cell surface remains a promising option. Micro/nano level features with various dimensions and distributions have been created on MC-Si crystal surfaces using a femto-second pulsed laser and the influence of surface topography on optical reflectance in the incident light wave length of 350 - 1000 nm have been studied and compared with the simulation results obtained using OPAL2 software. Experimental results indicate that surface textures on the wafer surface lead to the reduction of optical reflectance in the range of 20-35% in comparison with plain surface. Width of micro grooves have less significant effect on the optical reflectance in comparison with pitch between the micro grooves. Best reduction in reflectance is exhibited by the texture having a groove width of 30 µm and a pitch of 100 µm. A post texturing etching operation is found to have detrimental effect on the ability of micro/nano level features in decreasing the optical reflectance in the preferred wavelength of solar spectrum due to the flattening of nano level features created within the micro grooves due to laser texturing. [ABSTRACT FROM AUTHOR]

The purpose of this work is to study the effect of oil pocket shape and density on friction in reciprocating sliding. The experiments were conducted in reciprocating motion under starved lubrication conditions. Tribological tests were performed using an Optimol SRV5 tribotester. The frictional pair consisted of two discs of 42CrMo4 steel. One disc was laser textured. The oil pockets had circular and sandglass shapes. Disc samples of various texture shapes were characterized by the same pit-area ratios. The operating parameters were the same for all friction pairs. In most cases, surface texturing led to reductions in friction force value and scatter. For both dimple shapes, the best tribological properties were achieved for oil pocket density of 9%. When discs with circular dimples were tested, the highest resistance to motion was received for the highest pit-area ratio of 9%. On the contrary, the worst tribological performance of discs with sandglass-shaped oil pockets of sandglass shape were obtained for the largest oil pocket density of 22%. [ABSTRACT FROM AUTHOR]

The study is focused on investigating approaches for assessing the texture shape deviation obtained by laser structuring by remelting (Waveshape). A number of metrics such as Fourier spectrum harmonic ratio, cross-correlation coefficient (reverse value), and spectral entropy are investigated in terms of surface-texture shape deviation estimation. The metrics are compared with each other by testing two hypotheses: determination of target-like shape of texture (closest to harmonic shape) and determination of texture presence on the cross-section. Spectral entropy has the best statistical indicators for both hypotheses (Matthews correlation coefficient is equal to 0.70 and 0.77, respectively). The reverse cross-correlation coefficient proved to be close in terms of statistical indicators (Matthews correlation coefficient is equal to 0.58 and 0.75 for the first and second hypothesis), but is able to estimate the shape similarity of regular texture independent on its type. The provided metrics of shape assessment are not limited to the texturing process, so the presented results can be used in a broad range of scientific fields. [ABSTRACT FROM AUTHOR]

The clinical application of anastomotic instruments improves the efficiency of the digestive tract surgery. However, the stapler with titanium nails implanted is still controversial in terms of anastomotic complications, and further improvement and optimization are needed. The purpose of this study was to explore the optimal microtextured parameters that could enhance the bioactivity of titanium implants in vitro. Laser microtexturing technology was used to construct the groove-type microstructural surfaces with different parameters, and human gastric mucosal epithelial cells (GES-1 cells) and mouse fibroblasts (3T3 cells) were cultured on the surface of the titanium plates in vitro. The data of cell adhesion, cell proliferation and cell activity were obtained and statistically analyzed. The textured titanium plates meet the expected design. GES-1 and 3T3 cell adhesion were better in the surface of titanium plates in microstructural group than that in the polished group. GES-1 and 3T3 cells also showed higher proliferative activity in the microstructural group compared with the polished group. The laser textured titanium plates have good groove-type microstructure, which increase the surface roughness, change the surface wettability, promote the adhesion, proliferating and orderly growth of GES-1 and 3T3 cells, and show good biological properties. [ABSTRACT FROM AUTHOR]

It was mainly aimed at the study to make the optimization of laser parameters to obtain dimples with the desired shape and size. Carbon Fiber EPOXY composite (CF-EPOXY) surfaces were ablated by Nd:YAG laser which has a 1064 nm wavelength. Some important laser process parameters such as focus position, pulse energy, duration and number were optimized to achieve maximum aspect ratio, circular shape and minimum thermal defect. In addition, it has been determined that which laser parameters are more effective to obtain the desired quality surface. These different shapes and geometry of dimples could be used to improve some properties such as wettability, friction, etc. The pulse energy with an effective rate of 55.97 % is the most effective parameter to achieve the larger aspect ratio. The focus position is the most effective parameter with the rates of 66.18 % and 47.94 % to obtain both perfect circularity and minimum thermal defects respectively. Confirmation experiments were performed and the highest aspect ratio was found as 1.14, the best circular dimple and the minimum thermal effects outside the spot area were found with the rates of 1.021. These are the optimum results of 9 experiment sets in this study for each output. The results were supported by confirmation experiments and regression analysis. It can be concluded that the Taguchi method is reliable and saves time and materials. [ABSTRACT FROM AUTHOR]