Laser Surface Texturing Research Articles

Correction to: Nanosecond multi‑passes laser surface texturing on AISI 301LN TRIP steel

Correction to: Nanosecond multi‑passes laser surface texturing on AISI 301LN TRIP steel

Investigation of Laser Surface Texturing and Injection Molding Parameters in Advanced High‐Strength Steel‐Polyamide Direct Joining

This study investigates the joining of dissimilar materials, specifically galvannealed advanced high‐strength steel (AHSS) and glass fiber‐reinforced polyamide 6 (PA 6) to achieve lightweight automotive. AHSS and PA 6 are widely used in the automobile industry; however, a direct joining of those two materials is difficult owing to their great difference in physical properties. Therefore, laser surface texturing (LST) and plastic injection molding are adopted to join AHSS and PA 6, which can create a strong mechanical interlock between AHSS and PA 6, resulting in an excellent joint strength compared to other joining techniques. The effects of LST parameters (groove depth and hatch distance) and injection molding temperatures on the joint strength are examined. The maximum AHSS‐PA 6 joint strength is measured at 72.3 MPa. Additionally, the microstructure and mechanical properties of recast, which develops over the original metal surface by melting and resolidifying, are analyzed. Compared to the base metal, the recasts exhibit higher hardness due to smaller grain sizes. PA 6 fills the laser‐textured grooves and spaces between the recasts, acting as a mechanical interlock that enhances joint strength under tensile shear testing.

7-axis synchronization-integrated on-the-fly laser texturing system of freeform surface: design and development

Abstract While laser surface texturing (LST) is a promising manufacturing technique for surface functionalization, simultaneously realizing high precision and high efficiency in the LST of complex curved surface is challenging, due to continuously varied geometries of laser-matter incidence. In the present work, we propose a novel manufacturing system of 7-axis on-the-fly LST for complex curved surface, based on the integrated synchronization of 5-axis linkage motion platform with 2-axis galvanometer. Specifically, the algorithm for decomposing spatial texture trajectory on curved surface into low-frequency and high-frequency parts is established, based on which the kinematic model of synchronized 7-axis system is developed to derive the motion of each axis in both 5-axis linkage motion platform and 2-axis galvanometer simultaneously. Subsequently, the synchronized 7-axis LST system is experimentally realized, including the setup of mechanical stages integrated with optical path, the configuration of numerical control unit, and the development of processing software. Finally, case study of 7-axis on-the-fly LST of freeform aluminum surface is performed, and the advantages in terms of processing efficiency and texturing accuracy over 5-axis linkage LST are demonstrated. The correlation of reduced following errors between mechanical stages with the promoted performance of curved surface texturing by the 7-axis on-the-fly LST is further analyzed. Current work provides a feasible solution for establishing the manufacturing system for high performance LST of complex curved surface.

Investigating the Impact of Laser Surface Texturing on Tribocorrosion and Cytocompatibility Performance of Mg–Zn-hBN Nanocomposites

Investigating the Impact of Laser Surface Texturing on Tribocorrosion and Cytocompatibility Performance of Mg–Zn-hBN Nanocomposites

Porous mesh manifold for enhanced boiling performance

High-performance electronics are continuously demanding cooling of higher heat fluxes. Phase-change cooling, including pool boiling, is a useful approach to address this challenge; however, competition between liquid and vapor flows generally limit the heat fluxes that can be dissipated. A range of strategies to control these flows have been investigated previously, including capillary guides. Here a manifold structure formed from a metallic mesh is investigated to control the disposition of liquid and vapor phases above a pool fed boiling surface enhanced with porous structures. Copper mesh forms defined liquid flow paths, using capillary action to guide and distribute liquid evenly over the heated surface, along with open channels to facilitate vapor escape. The mesh provides a novel structure for liquid guidance that imposes low resistance to liquid flow while occluding a minimal area of heated surface underneath. The manifold performance is characterized in boiling fed by a pool of water above a laser-textured aluminum nitride heat dissipation surface with pin–fin structures having heights of 110 µm and spacing of 30 µm with a heated area of 5mm x 5mm. A maximum heat flux of 490 W/cm2 is reached with the manifold in the pool fed configuration, representing an increase of more than 65% over the porous pin fin surface alone. The maximum stable superheat observed for the manifold of 36K is 14K higher than that for the porous surface without the manifold. The factors limiting performance of the manifold are analyzed. High superheat is attributed to partial flooding of the boiling surface as suggested by the reduction in superheat using external suction. Similar systems and structures for enhanced two-phase cooling are compared.

Enhancing Laser Surface Texturing with Driving Training-Based Optimization: A Metaheuristic Approach

Enhancing Laser Surface Texturing with Driving Training-Based Optimization: A Metaheuristic Approach

Experimental Investigation on the Effect of Masked Multiple Passes Abrasive Waterjet Machining Surface Texturing on Coefficient of Friction

The surface texturing method is popular because of its ability to improve surface properties, specifically surface functioning, and friction control. It is a common technique used on material surfaces to improve friction performance. Laser surface texturing is the popular choice; however, this method suffers drawbacks such as cracking, heat-affected zone, and generation of hazardous fumes. The Abrasive Water Jet Machining (AWJM) was chosen is that, because the eroded material is carried by the waterjet, the process is clean and does not produce dust, chips, or chemical contaminants. This experiment examines the influence of AWJM and investigates how crater density and a multiple-pass machining path affect the stainless-steel friction characteristics when sliding in dry conditions. The texture was applied on the surface of stainless steel by masked multi-passes AWJM technique. According to the findings, there is less friction in craters with greater densities because there are more craters in the contact zone, which improves the trapping of debris particles and reduces friction, when the crater density rises from 4% to 18%, there is a greater chance of worn debris becoming trapped, which reduces friction. The coefficient of friction and crater roughness of the stainless-steel surface are all proportionally affected by the multiple-passes approach. The coefficient of friction increases with higher machining passes. There is more erosion and greater roughness when there are more jet passes. It is concluded that the masked multiple passes AWJM Surface Texturing technique has a significant impact on the Coefficient of Friction (COF).

Optimizing laser surface texturing effect via synergy of Burst-mode and advanced scanning paths

Optimizing laser surface texturing effect via synergy of Burst-mode and advanced scanning paths

Enhancing tribological performance of AISI 52100: the role of laser surface texturing in dry and lubricated conditions

Abstract Laser surface texturing (LST) is a valuable technique in surface engineering that offers significant improvements in the tribological behavior of metals and alloys. This study investigates the synergistic effect of incorporating hexagonal boron nitride (h-BN) as a solid lubricant with laser surface texturing on the tribological performance of AISI 52100. Dimple textures with varying pitch distances (100, 150, and 200 μm) were created on the surfaces of the mentioned materials using LST. The friction coefficient and wear behavior of both non-textured surface (NTS) and textured surfaces (TS) were analyzed under dry sliding (DS) and lubricating sliding (LS) conditions. Wear tests were conducted using a universal tribometer under a load of 10 N, a sliding frequency of 10 Hz, and a sliding time of 1250 s. The results demonstrate that the presence of dimple textures significantly influences the tribological behavior of the materials. In DS, the wear coefficient exhibits a significant reduction compared to NTS, with decreases of 88.1% for TSP-100, 28.5% for TSP-150, and 76.1% for TSP-200. In LS, the TSP-L-100 (h-BN NPS) surface demonstrates the lowest average wear coefficient among all textured surfaces. Specifically, the TSP-L-100 surface shows a remarkable 97.61% reduction in average wear coefficient compared to NTS. This study demonstrates the potential of LST combined with h-BN as a solid lubricant in improving the tribological properties of metals, offering valuable insights for surface engineering applications in various industries.

Finite Element Simulations and Statistical Analysis for the Tribological Design of Mutually Textured Surfaces and Related Experimental Validation

Abstract In the last few decades, micro-texturing has become a widely studied technique to modify the frictional behavior between surfaces in both dry and lubricated regimes. Among all the available techniques, the laser surface texturing appears to be fast, clean, and flexible, and thus a good candidate in realizing surface micro-patterns, also for the improvement of the tribological performance of automotive components when subjected to dry friction. For this reason, in the present work, the tribological response of four different patterns of micro-holes on two contrasting materials, specifically silicon carbide and carbon black have been investigated with a coupled experimental–numerical approach. The static and the dynamic friction coefficients have been extracted from the 25 different combinations of these surface textures including the flat counterparts. Then, the influence of the holes diameter, their density, and the material has been studied thanks to a multivariate linear regression. Specifically, it emerged that, in a dry regime, the most emerging parameter is the micro-holes diameter, for both static and dynamic frictions. Moreover, for both static and dynamic frictions, the material which more influences the effects of patterns to the overall frictional behavior is here the stiffest one. These insights for the design of micro-patterned surfaces with controlled frictional properties could be useful for those applications in which a dry friction regime is present.

Corrosion resistance and biocompatibility of magnesium alloy with bioactive glass-reinforced hydrogel composite coatings

Magnesium (Mg) alloy is a promising candidate for biodegradable implants; however, its rapid degradation can create an unstable physiological environment that hampers tissue regeneration. To address this challenge, a polyvinyl alcohol (PVA) hydrogel composite reinforced with bioactive glass (BG) particles was developed as a coating for Mg alloy pellets, which underwent laser surface texturing (LST) and salting-out processes. results demonstrate that these treatments significantly enhance both the adhesiveness and swelling of the hydrogel coating. Notably, electrochemical corrosion assessments reveal a marked improvement in corrosion resistance, with the Mg–B1-L-S specimen exhibiting the highest performance after salting-out treatment. Electrochemical corrosion assessments revealed a significant enhancement in corrosion resistance for Mg alloy with the hydrogel coating, with the Mg–B1-L-S specimen showing superior performance following salting-out treatment. Immersion tests in simulated body fluid (SBF) confirmed the protective effect of the coatings, indicating that the addition of BG particles and salting-out treatment reduced mass loss and maintained pH stability. Biocompatibility evaluations through in vitro viability tests and osteogenic differentiation assays indicate that the Mg–B1-L and Mg–B1-L-S specimens exhibit superior cell activity, surface adhesion, and osteogenic potential. These findings highlight the effectiveness of PVA-BG hydrogel composite coatings in enhancing the corrosion resistance and biocompatibility of Mg alloy implants, positioning this approach as a significant advancement in the development of biodegradable materials for biomedical applications.

Experimental characterisation and visualisation of a novel two-phase flexible heat transfer device

The importance of passive Flexible Heat Transfer Device (FHTD) in electronic cooling or space applications lies in their ability to provide efficient, reliable, and adaptable thermal management solutions. Heat transfer enhancement studies pertaining to FHTD developed to meet the thermal management demands of futuristic flexible electronic devices are presented in the current work. The possibility of extending the heat transport limit of FHTD beyond 24 W by limiting the maximum operating temperature to 60 °C is discussed. The superior performance of FHTD at varying heat loads from 5 W to 40 W at 45°and 90°bending angles is brought out compared with existing heat transfer devices like Flexible Heat Pipe (FHP) and copper thermal straps. The performance is reported in thermal resistance and equivalent thermal conductivity. A commercial dielectric liquid is used as a working fluid in FHTD to enhance the heat transfer limit employing phase change. The evaporator and condenser sections of the flexible section are made transparent to visualise the boiling and condensation phenomenon. Under steady-state operation at a 45°bending angle, The FHTD demonstrates a minimum thermal resistance of 0.73 K/W and a peak effective thermal conductivity of 8172 W/m K. The heat transfer coefficient ranges from 200 to 700 W/m2 K, consistent with values reported for heat pipes in the literature. Additionally, the study explores the impact of modifying the external surface texture to create more nucleation sites, thereby enhancing the performance of the FHTD. The results show that the laser-textured surface on the heat pipe condenser effectively reduces the onset of nucleate boiling for dielectric fluid by 3.5 °C and decreases the maximum temperature of the evaporator by 4.5 °C. The present work dictates the fundamental baseline for possible design choices of futuristic passive flexible heat transfer devices.

Enhanced tribological properties and cyto-biocompatibility of dental Ti6Al4V alloy via laser surface texturing

Currently, the application of titanium-based implants is hindered by challenges such as inadequate wear resistance and limited osseointegration. Surface texturing technique has been recognized as an effective strategy to improve the surface performances of metallic material. The present work adopts a nanosecond laser texturing technique to fabricate micro textures on the titanium substrate. Firstly, the influence of laser parameters on the texture morphology and quality were investigated. Subsequently, both isotropic and anisotropic surface textures were fabricated to examine the impacts of texture form on wettability, tribological behavior, and cell adhesion and proliferation. The obtained results reveal that both the two textures promote the surface wettability of Ti6Al4V alloy towards a hydrophobic direction. Furthermore, the anisotropic micro-groove texture and the isotropic micro-grid texture can reduce the wear rate of titanium alloy by 42.02% and 73.64%, respectively. However, from the perspective of cyto-biocompatibility, the anisotropic micro-groove texture is capable of triggering an excellent cell contact guidance phenomenon, leading to a dramatically accelerated proliferation rate and facilitating the bone tissue growth in a specific direction.

Superhydrophobicity induced antibacterial adhesion and durability of laser bidirectionally-textured zirconia surfaces with different inclination angles

Femtosecond laser bidirectional texturing with different laser energy densities and inclination angles was performed on zirconia (ZrO2) surfaces. The laser bidirectional texturing models under different inclination angles were constructed to predict the water contact angles (WCAs), and the superhydrophobicity induced antibacterial adhesion mechanism was analyzed. The results revealed that under the combined effect of the optimal laser energy density (7.0 J/cm2) and inclination angle (90°), the laser-textured ZrO2 surface could obtain a micro-nano dual-scale structure composed of periodic regular micro-cones and nanoparticles. This structure not only promoted the adsorption of carbon-containing hydrophobic groups from the stearic acid and the air to form a superhydrophobic surface with excellent chemical/mechanical durability and anti-fouling/self-cleaning abilities, but also minimized the contact area with the bacterial suspension (solid/liquid contact area ratio of 6 %) to enhance antibacterial ability. The optimal stearic acid-modified laser-textured ZrO2 surface exhibited an extremely low adhesive force (Fadhesive=6.69 μN) to the bacterial suspension, and thus achieved the highest antibacterial ratio of 85.3 %. This study is expected to enrich the application of ZrO2 ceramics in the medical field.

Effect of Laser Surface Texturing Process on Dry Sliding Wear Behavior of NiTi Shape Memory Alloy Used in Airplane

In this study, the effect of laser surface texturing (LST) applied to NiTi Shape Memory Alloy (SMA) on the dry sliding wear behavior of the material was investigated. After polishing and cleaning the material surface, a pitted surface texturing process was performed using a femtosecond laser under atmospheric conditions. After the surface texturing process, dry sliding wear tests were performed at room temperature. When the wear behavior of the laser-applied and non-laser-applied test samples was evaluated comparatively, it was determined that the coefficient of friction (COF) of the laser-applied samples under 1N load was approximately 17% lower. It was determined that the decrease in the COF value decreased with increasing load. However, the wear amount of the LSD-applied NiTi SMA was higher than the untreated sample. It was evaluated that this situation was due to thermal softening that occurred depending on the ablation geometry and dimensions.

Mechanical performance of laser-textured metallic surface

Mechanical performance of laser-textured metallic surface

Synergistic Effects of Surface Texture and Cryogenic Treatment on the Tribological Performance of Aluminum Alloy Surfaces

In order to improve the tribological properties of the 7075-T6 aluminum alloy used on the rotor surface, a combined method of cryogenic treatment and laser surface texture treatment was applied. Various tests, including metallographic microscopy, scanning electron microscopy, elemental analysis, microhardness measurements, were conducted to examine the wear morphology and modification mechanism of the treated 7075-T6 aluminum alloy surface. A numerical simulation model of surface texture was established using computational fluid dynamics to analyze the lubrication characteristics of V-shaped texture. The research finding that the 7075-T6 aluminum alloy experienced grain refinement during the cryogenic treatment process, enhancing the wear resistance of the V-shaped textures. This improvement delayed the progression of fatigue wear, abrasive wear, and oxidative wear, thereby reducing friction losses. The designed V-shaped texture contributes to reducing contact area, facilitating the capture and retention of abrasives, and enhancing oil film load-bearing capacity, thereby improving tribological performance. The synergistic effect of cryogenic treatment reduced the friction coefficient by 24.8% and the wear loss by 66.4%. Thus, the combination of surface texture and cryogenic treatment significantly improved the tribological properties of the 7075-T6 aluminum alloy.

Exploring the potential of laser-textured metal alloys: Fine-tuning vascular cells responses through in vitro and ex vivo analysis

Medical stents are vital for treating vascular complications and restoring blood flow in millions of patients. Despite its widespread effectiveness, restenosis, driven by the complex interplay of cellular responses, remains a concern. This study investigated the reactions of vascular cells to nano/microscale wrinkle (nano-W and micro-W) patterns created on laser-textured nitinol (NiTi) surfaces by adjusting laser processing parameters, such as spot overlap ratio and line overlap ratio. Evaluation of topographical effects on endothelial and smooth muscle cells (SMCs) revealed diverse morphologies, proliferation rates, and gene expressions. Notably, microscale wrinkle patterns exhibited reduced monocyte adhesion and inflammation-related gene expression, demonstrating their potential applications in mitigating vascular complications after stent insertion. Additionally, an ex vivo metatarsal assay was utilized to bridge the gap between in vitro and in vivo studies, demonstrating enhanced angiogenesis on laser-textured NiTi surfaces. Laser-textured NiTi exhibits a guided formation process, emphasizing their potential to promote swift endothelialization. These findings underscore the efficacy of laser texturing for tailored cellular interactions on metallic surfaces and offer valuable insights into optimizing biocompatibility and controlling cellular responses, which may pave the way for innovative advances in vascular care and contribute to the ongoing improvement of stent insertion.

Anti-corrosion and anti-icing properties of superhydrophobic laser-textured aluminum surfaces

Superhydrophobic surfaces have favorable properties in simultaneously reducing the negative effects of corrosion and ice accumulation. In this study, laser-texturing was employed as a facile and environmentally friendly surface method to prepare a surface with hierarchical roughness for subsequent grafting by immersion in an ethanol solution containing 1H,1H,2H,2H-perfluorodecyltriethoxysilane (FAS-10). Various analytical techniques were utilized to assess the characteristics of the laser-textured aluminum surfaces before and after grafting, such as a contact profilometer, optical tensiometer, scanning electron microscope with energy-dispersive spectroscope, and X-ray photoelectron spectroscope. These methods were used to evaluate surface roughness, wettability, morphology, and composition. The corrosion properties were evaluated through potentiodynamic and impedance measurements in a dilute Harrison's solution (DHS) composed of 0.35 wt% (NH4)2SO4 + 0.05 wt% NaCl. Additionally, freezing delay tests at various surface temperatures were performed to assess the surface's ability to prevent the freezing of water droplets on the treated surface. The laser-textured aluminum surface, featuring micro/nanostructures and a grafted nanoscopic perfluoroalkyl silane film, exhibited outstanding superhydrophobicity and enhanced corrosion protection. The developed surface has been shown to significantly delay the onset of ice nucleation and extend the freezing delay.

Investigation of the synergetic effect of oleophilic textured surfaces and MoS2 at different loads on the tribological performance of Ti64 alloy

In this research study, surface modification of Ti64 alloy was carried out using laser surface texturing (LST). The investigation aims to explore the effects of loads, oleophilic textured surfaces, and MoS2 as a solid lubricant on the friction and wear reduction of Ti64 alloy and AISI 52100 steel tribo-pairs. Three types of LST textures (Circular, triangular, and square textures) were created on the Ti64 alloy. Subsequently, tribological experiments were performed using a ball-on-disc universal tribometer at loads of 5, 10, and 15N with a 15 Hz frequency. The worn surface was analyzed using various methods, including optical microscopy, 3D-profilometer, FESEM, EDAX analysis, and Raman spectroscopy. The study compared the coefficient of friction (COF) and wear behavior of non-textured surfaces (NTS) with those of textured surfaces (TS) under both dry sliding conditions (DSC) and lubricated sliding conditions (LSC). The results demonstrated a significant reduction in the COF and wear coefficients on the TS. Specifically, the circular texture (CiT) exhibited a remarkable reduction of 39.3%, 63.83%, and 83.6% in wear coefficients compared to the NTS tested under DSC and LSC (using pure PAO-4 and PAO-4 + 1% wt MoS2) with sliding load of 15N. DSC showed abrasion, adhesion, and delamination wear, while LSC displayed mild adhesion, delamination, and tribo-layer formation on NTS and TS. The analysis indicated that the use of LST and solid lubricant nanoparticles on a Ti64 alloy would result in improved service life and better endurance in cutting tools and tribo-mating parts.