Surface Texturing Method Research Articles

Pulsed laser surface texturing enhancing corrosion resistance of rare-earth WE43 magnesium alloys in simulated body fluid environment

The addition of rare earth (RE) elements in Magnesium (Mg) alloys could optimize alloy microstructures and improve the mechanical property. The corrosion resistance however is a tough issue that limits its application as biomedical materials in human bodies. In this work, a green, fast and economical method of pulsed laser surface texturing (PLST) was employed to modify the RE WE43 Mg alloys and the corresponding corrosion resistance after the PLST treatment in simulated body fluid (SBF) was further examined. The microstructural results show that the surface exhibits petal-like microstructures and an oxide film composed of various oxides with remelting particles are also generated on laser-processed areas after PLST treatment. The electrochemical results reveal that the WE43 sample treated by PLST exhibits a superior corrosion resistance in SBF compared with the as-cast one. As for the PLST treated sample with 24 W, the corrosion potential (Ecorr) positively shifts from −1.788 V to −1.556 V after being immersed in SBF for 7 days, which is also nobler than that of the as-cast one, −1.915 V. While the corrosion current density (icorr) drops to the value of 8.3 μA/cm2, considerably lower than that of the as-cast sample, 1380 μA/cm2. The enhancement of corrosion resistance in the early stage is mainly due to the protective oxide film induced by PLST. Furthermore, long-term immersion in SBF further accelerates the formation of deposited hydroxyapatite (HA) products layer on petal-like microstructures, which would further contribute to its enhancement in corrosion resistance in the long-term service in human bodies.

Ripple formation on TA2 pure titanium surface induced by annular laser beam at low pressure environment

Formation of the micron-scale circular ripples on metal surfaces produced by continuous wave laser irradiation in low-pressure environment was investigated experimentally and numerically in this manuscript. It is found that splashing of the molten material and oxidation of the metal surface, which usually happened in the atmospheric environment, were avoided in low-pressure environment. Therefore, circular ripples were formed during the solidification process of the molten pool. Numerical simulations based on the finite element method (FEM) and the moving mesh method were applied to investigate the evolution of the flow field behavior of the molten pool. It is found that the Marangoni effect and capillary force during solidification process dominate the formation of the micron-scale circular ripples. In addition, the ripple spacing can be controlled by the temperature gradient. At the same power density, a higher temperature gradient on the molten surface can be produced by an annular laser beam, compared to a Gaussian beam, thus a denser circular ripple structure were produced, which were confirmed by the experimental results. The results of this paper may enrich the investigations on the metal surface texturing methods, laser vacuum processing and laser material engineering.

A high bonding tensile strength of CFRP ultrafast laser surface texturing method for surface damage repair

Carbon fiber reinforced polymer composite (CFRP) has a wide range of applications in aerospace, but it can cause varying degrees of damage in harsh service environments. Seeking a high-performance repair method is an effective way to save costs and ensure the service performance of CFRP components. In this study, a high bonding tensile strength of CFRP surface ultrafast laser texturing method for damage repair was proposed, which achieved complete removal of surface resin while retaining intact exposed fiber filaments. The difference in groove processing under unidirectional scanning and cross-scanning modes at different angles was explored. When the groove spacing was 0.2 mm and 0.4 mm, the surface resin was completely removed, the carbon fiber remained intact, and no debris was inside the groove. The groove morphology has a significant impact on the contact zone of the surface, which in turn affects the mechanical properties of the bonded joint. Cross-scanning can effectively improve surface roughness to increase the contact surface area. However, there is more fiber breakage, manifested as a groove weakening effect, which limits the improvement of bonding strength. In the 0° unidirectional scanning mode, the tensile performance of the joint is the best, improved by 61.6 % compared to manual processing.

Study on the solder flow in a narrow gap with metal surface texture

Obvious voids in the solder in a narrow gap is a common problem that greatly affects the reliability of mechanical connections. Due to its high heating rate, laser soldering causes more severe voids and even evolves into dispersion of the solder. A method of metal surface texturing is put forward, in which the texture gradient is used to directionally transport solder for lower dispersity, and the pattern design of texture is used to reduce the void rate. The directional transport of solder is realized through the differences in oxidation degree and microstructure of stainless steel surface under different ultrafast laser scanning speeds. The discharge of voids in the solder is achieved through the reservation of the central area in the solder and the oscillation during the laser heating process. Based on the present method, the aggregation of solder is achieved, with the void rate of 18 % and the joining strength of 10.4 MPa.

Enhancing the reliability of laser welded-brazed aluminum/stainless steel joints via laser-chemical hybrid surface texturing

Surface microtexture is a promising technique for enhancing the quality of heterogeneous joints. This study developed a novel surface texturing method to improve the reliability of laser welded-brazed aluminum/stainless steel joints. The method combined laser etching and chemical etching to create high-quality multi-scale surfaces with large grooves and small wrinkles. The designed microtexture promoted atomic transfer and induced the generation of nanoscale η-Fe2(Al,Si)5 phases during the welding-brazing process. It reduced the spreading activation energy along the groove direction, which enlarged the joining area. It also optimized the strain-stress distribution to enhance the deformation tolerance of the bonding interface throughout the structural strengthening mechanism. Through the synergistic regulation, the joint achieved a maximum line load of 495.9 N/mm, which was 61 % higher than the untextured joint of 307.5 N/mm. The joint performance reached 95 % of the Al/Al lap joint (519.3 N/mm) with the same welding parameters. This study provided new insights into the high-quality joining of aluminum/steel systems or other heterogeneous materials.

Theoretical study on surface texturing methods: a review

Theoretical study on surface texturing methods: a review

Anti-icing characteristics of hierarchical micro-dimple textured surface generated by 3D resonant vibration assisted machining

Anti-icing techniques are essential for safe functioning in applications such as aircraft and power transmission lines. In the present study, a long lasting and minimal maintenance required hierarchical micro-dimple surface textures were produced on a cylindrical specimen using a dual frequency surface texturing method. The water contact angle and time delay in freezing on five diverse type of micro-dimples with three different surface texture densities and non-textured surfaces were examined and compared experimentally. The textured surfaces showed an approximately 28 % increase in delayed time compared to non-textured surfaces. A size effect on the performance of micro-dimples was observed. Smaller size micro-dimples have better delayed time for higher texture density surfaces. The delayed time increases with the increase in micro-dimple size for optimum and low texture density surfaces. Introducing of hierarchical structures increased the delayed time by 8 % compared to single scale micro-dimple surface textures. The idea of introducing hierarchical micro-dimples as an anti-icing technique will directly result in improving the delayed time, which in turn reduces the load on the secondary system for ice removing and improves its working efficiency.

Adapting Shot Peening for Surface Texturing Using Customized Additive Manufactured Shots

Surface textures in engineering materials not only affect the reflective properties and aesthetics but if properly designed can modulate surface‐related properties such as wettability, fatigue, wear, corrosion, and scratch resistance. Herein, a new surface texturing method is introduced based on the conventional shot peening process. Custom shots are designed, and their surface texturing capability is investigated on acrylonitrile butadiene styrene (ABS) polymer substrates. A finite‐element model is developed to bombard the substrate using AISI 316 stainless steel customized shots. The generated unique textures are compared qualitatively by visual examination and quantitatively using the standard surface roughness parameters. As a proof of concept, preliminary experiments are performed using a candidate custom shot and a spherical shot to treat the ABS sheets. The results highlight the high potential of the shot peening technique paired with additive manufacturing for customizing the peening media to be used for surface texturing polymeric materials.

Modification of the roughness of 304 stainless steel by laser surface texturing (LST)

Surface texturing is one of the most effective approaches to modifying the surface to improve many properties: tribological, corrosion resistance, microhardness and others characteristics of a number of engineering materials. Among the surface texturing techniques developed in recent years, the most widely used method is the laser surface texturing method (LST) due to its high flexibility, superior texturing accuracy and good process controllability and reproducibility. With its rapid development, LST has attracted considerable attention in various industries such as automotive, biomedical and aerospace. The present study considers the changes in roughness in different modes of laser texturing of stainless steel specimens 304. The effects and role of individual laser parameters on the change in roughness are analyzed as a main characteristic of the surface properties of the processed material. Heating and its surface melting is one of the studied effects and its role in changing the roughness. The focus of the study is on the process of laser–material interaction as a function of absorbed energy density, pulse frequency, scan rate, and overlap coefficients leading to different effects of LST parameters. It has been found that increasing the energy density, accompanied by a decrease in the frequency and speed of scanning, can increase the surface roughness.

Theoretical and numerical investigation of micro-textures fabrication by ultrasonic surface rolling process

Surface texturing is a potential approach to achieving excellent surface performance. To realize high precision and efficiency in micro-texturing fabrication, a surface texturing method utilizing an ultrasonic surface rolling process is proposed. Firstly, the feasibility and geometric controllability of micro-texture preparation using ultrasonic surface rolling process are analyzed. Then, a contact theory model of ultrasonic rolling texturing process is established, which can describe the geometric relationship of the micro-texturing generation region. Based on the elastic–plastic theory, simulations of single-pass and multi-pass ultrasonic rolling texturing processes are developed to elucidate the formation and strengthening mechanism of micro-textures, and further characterize the effects of ultrasonic rolling machining parameters on micro-textures. A series of validation tests of ultrasonic rolling texturing are implemented on AISI 5140 steel. Simulation and experimental results show that the ultrasonic surface rolling process can fabricate micro-groove arrays with the periodic distribution. The validity of the theoretical and finite element models is confirmed by the comparison results. It is demonstrated that the ultrasonic rolling texturing process is a feasible and efficient way to fabricate controllable micro-textures.

Effect of the micro-textured piston on the performance of a hermetic reciprocating compressor

A hermetic reciprocating compressor is one of the most critical parts for the energy efficiency of a household refrigerator. Piston-cylinder contact in the hermetic compressor accounts for most of the energy loss. The tribological performance of the piston-cylinder pair can be enhanced by introducing micro-texturing on the piston surface. In this research, an experimental study is presented to tribologically assess the effect of the micro-textured piston on the performance of the hermetically sealed reciprocating compressor. The micro-texture on the piston surface was prepared by the laser surface texturing method. Four different micro-textures were studied: radial micro-grooves, axial micro-grooves, mesh micro-grooves, and micro-dimples. The textures’ size, shape, and depth were studied using scanning electron microscopy (SEM) and white light interferometry (WLI) techniques. The results were compared with the non-textured piston compressor. It was found that the radial, axial, and mesh micro-grooves pistons have a negative effect on the coefficient of performance of the hermetic reciprocating compressor. However, the piston with the micro-dimples texture increased the compressor's coefficient of performance by 1%. Refrigerant leakage from the piston-cylinder clearance was also investigated and it was observed that micro-dimples on the piston surface decrease the refrigerant leakage by 35% due to the presence of a continuous oil film between piston and cylinder. The compressor's cooling capacity (Qc) was observed to be increased by 1 W in the case of a micro-dimpled piston.

Effect of Micro-Dimple Geometry on the Tribological Characteristics of Textured Surfaces

The introduction of external surface features on mating contact surfaces is an effective method to reduce friction and wear between the contact surfaces. The tribological properties of the contact surfaces can be improved by controlling the geometrical parameters (shape, size, depth) of the surface texture effectively. In the present study, the tribological properties of Al6061-T6 cylindrical workpieces with various micro-dimple-texture geometries and an AISI 52100 steel stationery block are tested experimentally, in a rotating cylinder-on-pin configuration of the friction test. The dual-frequency surface texturing method is employed to create micro-dimple textures using a polycrystalline diamond tool. The effect of a hierarchical micro-dimple texture is then investigated under boundary lubrication conditions. Hierarchical micro-dimples, with an increase in length, show a lower friction coefficient under high load and sliding speed conditions. Secondary hierarchical nano-structures help in improving the tribological characteristics by generating an additional hydrodynamic lift effect.

Fabrication of the high-precision micro-structure array using a phase shift modulation of superimposed oscillation in ultra-precision grinding.

Various micro-structure surface texturing methods have been used to produce optical functional surface in the grinding, such as the textured grinding wheel, wheel path control and off-spindle-axis grinding. However, those grinding technologies are inherently challenged to employ in large-scale surface grinding due to the extremely high requirement for wheel cutting profile dressing. In this study, a novel phase shift modulation based on wheel oscillation motion was proposed to generate the micro-structure array in ultra-precision grinding. The phase shift effect involved in the surface micro-structure generation is investigated, in which the role of the second phase shift on superimposed mode and micro-waviness forms is discussed. A theoretical model based on the tool superimposed oscillation is established to study the micro-structure texture generation mechanism by considering the second phase shift. The influence of modulation frequency in the case of phase shift and out of phase shift on the surface texture generation both for the striation pattern and micro-structure is compared to clarify the transition between the continuous grooves and the discrete micro-structure array. The study indicates that the phase shift modulation represents a novel paradigm for fabricating micro-structure array with considerable capability and high efficiency in ultra-precision grinding.

Review on Surface Texturing Method for Solar Cell Efficiency Enhancement

Sun oriented cell are also known as Photoelectric (PE) cells, which labor to transform sunlight specifically into electricity, Photoelectric cells are attached electric powered and conveniently arranged within a wide outline known as a sun based board. The efficiency of the sun powered cell is turns on the number of consume photons which are absorbed in the consumer sheet of sun powered cell. However, the low absorption rate of the absorber material and light reflection in the surface of material and the material interfaces of the glass absorbers will reduce the conversion of solar energy. The effect of the energy conversion can be upgrade by modifying the surface morphology of the solar cell. In this article review of Exterior by different Texturing Method to increase efficiency enhancement, minimum waste energy of light of the sun and to get a maximum efficiency for the Sun Powered Cell Effective Upgrade has been investigated.

Fabrication of Superhydrophobic Surface on Low Carbon Steel

The purpose of the present work is to fabricate superhydrophobic surfaces on commonly used low carbon steel (AISI 1018). Laser surface texturing (LST) method is used for creating circular textures on mild steel surface having the diameter and pitch of 200 μm each. Two different materials (wax & Candle soot) are used to decrease the surface energy of the mild steel. It is observed from the results that the water contact angle of untreated surface increases from 87° to 155° after LST and lowering the surface energy by using wax, followed by candle soot.

Tribological properties of hierarchical micro-dimples produced on a cylindrical surface by dual-frequency texturing

An experimental investigation was performed for investigating the tribological performance of micro-dimple surface texture patterns on a cylindrical surface in a realistic operating environment of starved lubrication. Micro-dimples were generated by a dual-frequency surface texturing method, in which a high-frequency (16.3 kHz) three-dimensional (3D) vibration and a low-frequency (230 Hz) one-dimensional (1D) vibration were applied at the tool tip simultaneously, resulting in the generation of the hierarchical micro-dimples in a single step. Rotating cylinder-on-pin tribological tests were conducted to compare the tribological performance of the non-textured reference specimen and micro-dimple samples. The effect of surface textures generated with various shape parameters (long drop and short drop), dimension parameters (length and surface texture density), and operation parameters (load and sliding velocity) on the tribological performance was evaluated. Stribeck curves indicate that the hierarchical micro-dimples exhibit a lower coefficient of friction than the reference specimen in the high contact-pressure regions. It is also observed that variation in the length of a micro-dimple, the shape effect, is the major factor affecting the friction response of the textured surfaces. The generation of additional hydrodynamic pressure and lift effect by hierarchical structures is the main reason for the improved performance of hierarchical micro-dimple surfaces.

Temperature-dependent dynamic fouling on superhydrophobic and slippery nonwetting copper surfaces

• Presents, for the first time, temperature-dependent dynamic fouling on nonwetting surfaces. • Elucidates, for the first time, effects of texturing method and surface type on fouling behavior. • Nonwetting surfaces show up to 75% less scaling compared to regular surfaces. • Electrodeposited surfaces offer better scaling resistance compared to etched surfaces. • Presents Hill-Langmuir model, for the first time, to describe the time evolution of scaling. Bioinspired, superhydrophobic and slippery liquid infused surfaces that offer nonwetting characteristics have been explored in recent years for fouling mitigation. However, most of the studies are in the context of biofouling or under static immersion at ambient temperature conditions that are not reflective of the dynamic flow environment in practice. This article presents, for the first time, a systematic study of dynamic fouling of superhydrophobic (SHS) and slippery lubricant-infused surfaces (LIS) over a range of flow and temperature conditions. Copper metallic surfaces were textured via electrodeposition or etching and further functionalized to achieve SHS and, additionally, infiltrated with a lubricant to fabricate LIS. The nonwetting surfaces were studied for their fouling behavior in a rotating Couette flow of a supersaturated calcium sulfate solution at different rotational speed and temperature. Fouling mineral mass accumulation on the different surfaces was measured as a function of time over a period of days using inductively coupled plasma mass spectroscopy and the fouled surfaces were investigated using scanning electron microscopy. Both SHS and LIS showed superior anti-scaling performance at all ranges of variables. An analytical Hill-Langmuir model is presented, for the first time, to describe the time evolution of scaling within 20% accuracy over the range of parameters studied. The study is the first to juxtapose two surface texturing methods, electrodeposition and etching, and two nonwetting surface types, SHS and LIS, subject to a common suite of experiments to elucidate fundamental understanding of mineral fouling on nonwetting surfaces.

Surface Texturing Technique Based on Ultrasonic Turning for Improving Tribological Properties

Tribological properties such as lubrication, friction, and wear resistance greatly affect machine operation efficiency, performance, and service life. Surface texturing methods such as scraping can be used to improve these properties. Scraping creates many small depressions on the target surface. These depressions, which are evenly distributed, function as oil holes and thus improve lubrication performance. This paper describes a surface texturing technique based on ultrasonic vibration-assisted turning (UVAT) that simultaneously improves tribological properties and machinability. In UVAT, the cutting tool is oscillated mainly in the principal direction. Vibration in the radial direction, which is induced by Poisson deformation, periodically digs up or pushes the workpiece surface in the radial direction, creating a textured surface. A surface subjected to UVAT has periodic depressions along the workpiece rotation direction. The texturing rate of UVAT is up to 6700 mm2/min, which is higher than that of manual scraping. To evaluate the tribological performance of a surface textured by UVAT, the friction coefficient between a stainless steel pin and the surface was measured under oil dipping conditions. The results of friction experiments show that the friction coefficient of the UVAT-treated surface and its fluctuation were lower than those of a conventional turned surface. The UVAT-treated surface had stable friction properties.

Electric Discharge Assisted Surface Texturing of Stainless Steel 304

Surface texturing methods are used to engineer surfaces with specific properties in terms of wettability, friction, adhesion, or optical response. Hydrophobic surfaces, i.e., surfaces with minimal wettability, have tremendous applications across various fields; however, texturing methods for developing such surfaces over large areas with complex geometries are limited. This work investigates the process of electrical discharge machining for creating hydrophobic textures on stainless steel (SS304). The effect of EDM parameters such as the discharge current and tool feed on the surface roughness, water contact angle, and tool wear is investigated via experimentation. An increase in the current and tool feed improves the hydrophobicity of the surface by creating a rougher surface while worsening the tool wear rate.

Enhanced light harvesting in GaAs thin-film solar cells using plasmonic gold (Au) nanoparticle absorbers

Surface texturing methods are often used in thin-film solar cells (SCs) to achieve effective photon trapping. However, such approaches have a detrimental impact on cell performance and are not suitable for thin-films. Plasmonic light trapping using metal nanoparticles (NPs) is one of the promising technique for achieving superior optical absorption in thin-film SCs with less material usage. In this article, to improve the optical performance of GaAs thin-film SCs, a uniformly distributed Gold (Au) nanoparticle (NP) array is introduced at the top of transparent indium-tin-oxide (ITO) electrode. The Au NP array functions as an antireflection layer, increasing light harvesting in active layer for both visible and infrared (IR) wavelength regions. By performing 3-D finite-different time-domain (FDTD) analysis, we have presented a comparative optoelectronic study of the GaAs SCs with and without Au NPs. Photovoltaic parameters such as optical absorption (A (λ)), photogeneration density (Goptical rate), and photocurrent density (Jsc) are used to evaluate performance of the structures. The proposed thin-film SCs with Au NPs achieved an optical absorption of 60% (planar) and 77% (NW array) with a remarkable photocurrent of 22.8 mA/cm2 (planar) and 26.7 mA/cm2 respectively.