Effect Of Laser Surface Texturing Research Articles

Effect of laser textured surface with different patterns on tribological characteristics of bearing material AISI 52100

Chrome steels are used in bearings since they possess high strength and wear resistance. However, when those parts are in service, failure happens due to sliding friction before the lifetime. To improve the durability of the American Iron and Steel Institute (AISI) 52100 chromium steel, in this work, the effect of laser surface texturing (LST) was analyzed. With the different patterns of circle and ellipse comparing with the untextured samples, the wear behavior was investigated using the pin-on-disc tribometer. The lubricant used for wear analysis is semisolid lithium grease National Lubricating Grease Institute lubricant (SKF NLGI-3). Sliding wear analysis was conducted at different loads of 10 N, 30 N and 50 N for the sliding speed of 750 r/min and 1400 r/min. The wear morphology was analyzed using a scanning electron microscope(SEM). The roughness of the samples was found using a white light interferometer. The effect of different patterns like circle and ellipse, alter the friction and wear properties of chromium alloy was observed compared with the untextured samples. LST shows considerable reduction in friction and wear for ellipsoidal pattern compared with the circular pattern because of wear debris and lubricant getting trapped.

Corrosion Wear Performance of Pure Titanium Laser Texturing Surface by Nitrogen Ion Implantation

The poor tribological performances of titanium have significantly limited its applications in the field of artificial joints. In order to solve problems regarding the wear and corrosion of artificial joints in the body, we fabricated the composite materials utilizing the combination of laser surface texturing and nitrogen ion implantation technology, and investigated the effect of laser surface texturing, nitrogen ion implantation, and different dimple area densities on tribological performance. The results show that the textured surface could reduce the friction coefficient and improve the wear resistance, and the optimum dimple density was found to be 25%. After N ion implantation, the wear resistance of the textured sample was further improved, due to the formation of the nitride layer. Moreover, as shown by the electrochemical test results, the corrosion resistance was enhanced significantly. The friction coefficient decreased the most, and the wear resistance increased by 405% with the lowest wear rate of 0.37 × 10−3 mm3/N·m. However, the specimen with a dimple density of 60% had the worst wear resistance. The results of the study provide a basis for the development and application of artificial joint materials.

The effect of laser surface texturing to inhibit stick-slip phenomenon in sliding contact

Stick-slip phenomenon in some mechanical structures, especially in machine tools, should be eliminated or inhibited, otherwise the vibration will occur and the position error will inevitably be obtained. In this study, different kinds of surface textures were carried out on the lower samples of the pin-on-disk contact. The starting process of the machine tools was simulated on an Rtec-Multi-Function Tribometer. The stick-slip phenomenon was observed in each kind of samples. However, the stick-slip phenomenon of smooth sample is larger than that of the textured samples. The bulge-textured surface shows excellent anti-stick-slip effect, and the critical stick-slip speed of bulge-textured surface is 95.9% lower than that of the smooth surface. Simultaneously, the anti-stick-slip effect of bulge-textured surface is superior to that of the dent-shaped texturing surface. What’s more, when the amount of lubricating oil is 15 mL, the standard deviation values of friction coefficient and critical speed of stick-slip phenomena (rotational speed when the standard deviation of friction coefficient is abrupt) are the lowest at different rotational speeds. It can be predicted that the bulge textures and adequate amount of lubricating oil (15 mL) can eliminate stick-slip phenomenon when processed in the surface of the machine tool because the bulge textures and adequate amount of lubricating oil can improve frictional state effectively and avoid the slip of the contact surface.

Fabrication of controllable wettability of crystalline silicon surfaces by laser surface texturing and silanization

This paper aims to explore the effects of laser surface texturing and chemical modifications by silanization on the wettability of silicon surfaces. To effectively prepare super-hydrophobic surfaces on silicon, a process using laser texturing with following silanization treatment is used to modify the surface. The surface wettability is evaluated by water contact angle (WCA). To ascertain the effect of laser texturing on wettability, the morphological and metallurgical modifications of the surface were investigated by scanning electron microscopy (SEM), white light confocal microscope and X-ray photoelectron spectroscopy (XPS). It is found that the fresh laser-processed silicon surface is super-hydrophilic, which is in line with the Wenzel model. A super-hydrophobic surface with a WCA >150° was successfully obtained after silanization treatment. Silanization by a concentration of 0.72 wt% 1H, 1H, 2H, 2H-perfluorodecyltrichlorosilane with 2 h of immersion time was found to be the most effective condition for achieving super-hydrophobic silicon surfaces. The effects of acids, alkalis and salts on wettability have also been assessed. The results indicate that as-prepared silicon samples with a fluoride coating can be normally used in acid condition but not suitable for use in alkaline and salty environments.

Tribological behavior of laser textured nodular cast iron surface

PurposePrevious publications were mainly focused on the effect of textures under lubrication. Under dry sliding, area ratio of surface texturing (pit area ratio) and diameter of pit affect the tribological behavior. This paper aims to investigate the effect of laser surface texturing on tribological behavior of nodular cast iron under dry sliding.Design/methodology/approachPit-like textures with different diameters and spaces were fabricated by laser on nodular cast iron (QT600-3). Using nodular cast iron (QT600-3) as the disc specimen and resin matrix composites (UCV018) as the pad specimen, the tribological test was performed with pin-on-disk reciprocating tribo-tester.FindingsThe coefficient of friction (COF) of the non-textured specimen was larger than that of the textured one. For the same pit diameter, a larger pit area ratio induced a slight decrease of COF, while wear volume decreased significantly. The pit diameter induced a slight decrease of COF as the pit area ratio, but its effect was weaker.Practical implicationsThe experimental studies will help to improve the brake system such as structure modeling of brake disc. Predicting the performance and life of the brake disc in vehicle based on tribological behavior checked in test, it was proved that pit-like texture had application value in vehicle brake system.Originality/valueThis paper showed that the effect of pit area ratio on friction and wear was greater than that of pit diameter. The experimental results will be useful to the design on safety brake disc.

Effect of laser surface texturing on wear resistance of nickel based superalloy

PurposeThis paper aims to investigate the effect of laser surface texturing (LST) on the wear behavior of C-263 nickel-based superalloy and to identify the optimum wear operating condition.Design/methodology/approachC-263 nickel-based superalloy was selected as substrate material and pico-second Nd-YAG laser was used to fabricate the waviness groove texture on their surface. Wear experiments were designed based on Box-Bhenken design with three factors of sliding velocity, sliding distance and applied load. Wear experiments were performed using pin on disc tribometer. Morphologies of textures and worn-out surfaces were evaluated by scanning electron microscopy and energy dispersive spectroscopy. Surface topographies and surface roughness of the textures were evaluated by weight light interferometry. The response surface methodology was adopted to identify the optimum wear operating condition and ANOVA to identify the significant factors.FindingsLST improves the wear resistance of C-263 nickel-based superalloy by appeoximately 82 per cent. Higher wear rate occurs at maximum values of all operating conditions, and applied load affects the coefficient of friction. Applied load significantly affects the wear rate of un-textured specimen. The interaction of sliding velocity and applied load also affects the wear rate of textured specimens. The optimum parameters to get minimum wear rate for un-textured specimens are 1.5 m/s sliding velocity, 725 m sliding distance and 31 N of applied load. For textured specimens, the optimum values are 1.5 m/s sliding distance, 500 m sliding distance and 40 N of the applied load.Originality/valueLiterature on laser texturing on nickel-based superalloy is very scarce. Specifically, the effect of laser texturing on wear behavior of the nickel-based superalloy C-263 alloy is not yet reported.

Effect of laser surface texturing (LST) on tribological behavior of double glow plasma surface zirconizing coating on Ti6Al4V alloy

In the present work, double glow plasma zirconizing technique combined with laser surface texturing (LST) were applied to improve the wear resistance of Ti6Al4V (TC4) alloy. A zirconium coating (Zr-coating) was firstly synthesized on TC4 alloy by double glow plasma surface zirconizing. Laser surface texturing (LST) was subsequently conducted to produce uniform dimples on the surfaces of Zr-coating and raw TC4 alloy. The dimple texture with a diameter of 300 μm and gradient densities of 5%, 7%, 11% were distributed in a square array on the surfaces of coated and uncoated TC4 alloy disks, respectively. Comparative assessments on the wear resistance of the related Zr-coating and TC4 alloy were carried out using a ball-on-disk wear tester. The results showed that the Zr-coating with a thickness of about ~50 μm, was tightly adhered to the TC4 alloy matrix. The textured specimens with a texture density of 5% revealed the lowest mass loss values in comparison to other samples, and the wear rate decreased by 20% and 26.6% compared with that of the TC4 alloy and Zr-coating without dimple texture on their surfaces. The wear rate value of the four tested samples were finally sorted in the sequence of the duplex treated TC4 < zirconized TC4 < textured TC4 < polished TC4.

Synergistic effect on the tribological properties of tool steel through the use of laser surface texturing channels and nanoparticles

Many studies have been focused on the positive effect of laser surface texturing (LST) for tribological performance of several metal mechanic tools and machine elements. Different geometries have been studied and benefits have been found in the two main tribo characteristics: coefficient of friction (COF) and wear. The most analyzed geometry, because of its ease of manufacturing, is the circle. Not enough has been studied respective of the effect of the orientation of micro channels and nanoparticles in lubricants together. This work shows the results obtained by adding the synergistic efforts of the use of laser surface texturing channels in two orientations (vertical (V) or horizontal (H)) and the use of TiO2 nanoparticles dispersed at 0.05 wt% within a poly alpha olefin (PAO4). A T-05 conformal contact block-on-ring equipment was used for the tribological tests (COF and wear values) according to ASTM G77 standard with continuous revolutions ensuring constant lubrication. The output parameter of surface finish was measured using a 3D Alicona Edgemaster surface analyzer. Reductions of up to 76% and 89% were reached for COF and wear respectively for laser surface textured test blocks. The addition of nanoparticles was able to reduce also COF by 68% and 97% in wear; also improvements in roughness was founded when micro channels and nanoparticles (NP) was used together in values up to 50%. With this study the synergistic effect of channel texturing (including orientation of the channels) and the use of nanoparticles on lubricants in conformal contact processes such as for deep drawing processes was demonstrated.

Experimental analysis of the effects of laser surface texturing on tribological properties of PTFE/Kevlar fabric composite weave structures

Abstract Laser surface texturing (LST) has been proved to be exceedingly effective in reducing friction and wear in a tribosystem, but there is very little research carried out on the application and research of LST in dry friction. In this study, the round dimple-like LST was fabricated on 45# steel surface and its effect on tribological properties of PTFE/Kevlar fabric composite weave structures was thoroughly investigated in dry friction. The associated results showed that the utilization of preferable microconcave parameters consisting of 100 μm in diameter, 30% in area density and 0.1 for the depth-diameter ratio could decrease the friction coefficient and wear rate by 64 and 82%, respectively when compared with those for untextured surfaces. In addition, different parameter of microconcaves appeared to induce significant impact with mutual interactions to affect the LST. It was found that the LST tended to accelerate the formation of transfer films due to the storage feature of microconcaves for improving the tribological properties. The long period test results suggest that the coefficient of friction will change after a period about an hour (sliding distance of 1000 m), that is to say, after about 23 h, untextured surfaces would be basically the same as the friction coefficient of textured ones.

Effect of laser surface texturing on friction behaviour in elastohydrodynamically lubricated point contacts under different sliding-rolling conditions

The Laser Surface Texturing (LST) technique has been largely investigated to improve the tribological performance of lubricated contacts. The present contribution is aimed at scrutinizing the influence of three texture configurations fabricated by LST on the tribological performance of elastohydrodynamic (EHD) point contacts under different slide-to-roll ratios (SRR), entrainment velocities and inlet temperatures. Friction experiments were conducted through a series of ball-on-disk tests in the MTM-2 (Mini-Traction Machine) tribometer. Main results showed that the texture configurations promoted significant effects under boundary and mixed lubrication conditions, and also affected the full-film EHD regime at higher temperatures. Furthermore, the tribological performance of textured samples was strongly related to the texture depth. Shallower texture designs (∼0.5 μm) reduced friction compared to untextured material, whereas deeper features (>1 μm) generally led to detrimental results. In general, dimples configuration decreased the lift-off speed and promoted full-film EHD conditions for a larger range of speeds, whereas radial curved grooves yielded to friction reduction under mixed lubrication conditions, moving the transition from boundary to mixed regimes to lower speeds, especially for intermediate lubricant viscosity.

Effect of laser surface texturing on tribological behaviour of grey cast iron

Effect of laser surface texturing on tribological behaviour of grey cast iron

Effect of laser surface texturing on tribological behaviour of grey cast iron

This work aims to study the effect of laser surface microtexture on the sliding behaviour of grey cast iron, which is used as a liner material in internal combustion engines. The sliding wear analysis was conducted at different sliding speeds (200 rpm, 400 rpm, and 600 rpm) and a normal load of 10 N. Laser machining system was used to create micro-dimples with texture densities of 13.45% and 6.37%. The dimple sizes were observed using a scanning electron microscope, and the surface roughness was measured using the white light interferometer. The sliding wear results show that the textured samples with 13.45% densities in higher viscosity 146 mPas oil show better wear resistance with 0.1828 mm3'm wear rate and reduced friction coefficient of 0.1973. The wear morphology of the textured samples confirms the abrasive wear mechanism with minimum material removal compared with the non-textured specimen for the given applied load and sliding speed.

Effects of laser surface texturing on tribological properties of Ti-6Al-4V in hydroxyethyl-cellulose water-based lubrication

PurposeThis paper aims to investigate the effect of laser surface texturing on the tribological performance of Ti-6Al-4V disks sliding against Si3N4 balls under hydroxyethyl-cellulose water-based lubrication. The friction coefficients and wear losses of textured and untextured disks were measured and compared. The results indicate that the texture patterns can lead to reduction of friction and wear in the condition of water-based lubrication.Design/methodology/approachSolutions of hydroxyethyl cellulose were used as water-based lubricants. To find the optimal laser texturing parameters for the best performance enhancement, three line-like patterns were fabricated onto the disks and three machining parameters were used for each type of pattern. Tribological tests were conducted in rotation sliding with ball-on-disk contact configuration on UMT-2.FindingsA higher density of texture lines leads to a larger friction and wear reduction. Compared with untextured disks, the friction coefficient is reduced from 0.043 to 0.028 for textured disks. Some unworn parts were detected in the contact region of the balls against textured disks, which were not found on the balls against untextured disks. The worn surfaces indicated that periodic geometry of the contact track was rebuilt during run-in period, which was beneficial for the formation of lubricant films.Originality/valueIn this work, laser surface texturing was used to reduce the friction and wear of Ti-6Al-4V specimens in water-based lubrication, which can be used to improve the tribological performance of Ti-6Al-4V components in mechanical equipment.

Tribological and vibrational effects of laser surface texturing on steel-steel sliding contact

Laser surface texturing (LST) not only can significantly improve the tribological performance of various tribological contacts, but also can significantly reduce the frictional noise and vibrations generated from sliding contacts. In order to investigate the tribological effect of laser surface texturing, sixteen stainless steel specimens with different surface textures, and different textured area ratios are designed and processed on the surfaces of specimens by means of laser surface texturing technique. Four different operation speeds are carried out using a standard friction and wear testing machine (UMT-TriboLab) under rich oil lubrication condition. The experimental results show that the diameter of surface circular dimple had the most significant effect on the tribological properties of steel-steel sliding contacts, followed by texture depth, texture area density, and sliding speed. The effect of laser surface texturing on the frictional noise and vibration generated from steel-steel in dry sliding contacts is also investigated. Laser surface texture has significant effect on the reduction of noise generated from steel-steel dry sliding contacts in both time and frequency domains. The conclusion is that laser surface texturing has significant effects on the tribological, vibrational, and other physical performance of functional surfaces. To get the best tribological and vibrational performance, the functional surface texture should be optimized considering the coupled effects of surface texture, lubrication, and contact condition.

Topographical effects of laser surface texturing on various time-dependent wetting regimes in Ti6Al4V

Laser surface texturing (LST) processes have great potential to alter surface wetting properties of widely known bioactive Ti–6Al–4V alloy. Micro-pillars arrays of different topography are produced by Nd:YAG laser of 1064 nm wavelength to investigate the influence of its physical and geometrical parameter on wettability. Micro-textures named as: THS (high density, square pillars of 30 × 30 μm), TMS (medium density, square pillars of 60 × 60 μm), TLS (low density, square pillars of 170 × 170 μm), TLL (low density, landscape pillars of 300 × 100 μm) and TLP (low density, portrait pillars of 100 × 300 μm) are produced to analyze the effect of texture areal density, aspect ratio and shape over surface wetting phenomenon. It is observed that on the flat textured surface shows hydrophilic and spontaneous wetting behavior up to 24 h after machining. Percentage increment in water contact angle (CA) value varies with time, maximum increase in CA was found to be in THS (215%) followed by TMS (197%), TLS (166%), TLP (144%) and TLL (122%) after 20 days of machining (as compared with the untextured surface). The response of the textured surface to spontaneous wetting behavior with respect to varying viscosity is also studied and validated through Washburn's model. It is found that early viscous regime of capillary rise in the textured surface can be altered by regulating the geometrical parameters of the micro-textures array. Time taken to rise up to 40 mm by low, medium and high viscosity fluids are 200 s, 600 s and 9334 s respectively. The texture (THS) with highest areal density micro-pillars of 60 μm width exhibits maximum capillary action.

Effect of laser surface texturing on tribological properties of polyimide composites in the application of traveling wave rotary ultrasonic motor

PurposeThe purpose of this paper is to investigate the effect of laser surface texturing on the tribological properties of polyimide composites and the output performance of traveling wave rotary ultrasonic motor.Design/methodology/approachThe surface texturing on polyimide composites specimens were fabricated by laser ablation process of different dimple densities, and then the tribological properties were tested by a flat-on-flat tribometer under dry conditions. Finally, the output performance of the traveling wave rotary ultrasonic motor was tested to verify the effectiveness of dimples surface texturing.FindingsThe results show that surface texturing can greatly enhance the friction coefficient of contact interface, especially the specimen with a dimple density of 7.06 per cent exhibited the highest friction coefficient among the specimens. When the input voltage is 500 V, the output power, locked-rotor torque and output torque of ultrasonic motor with textured PI of 7.06 per cent dimple density as friction material at the speed of 100 r/min increased by 13.8, 19 and 12.8 per cent compared to that of the untextured PTFE, respectively. When the ultrasonic motor reverses, the output performance is increased by 20.9, 40.3 and 17.7 per cent, respectively.Originality/valueSurface texturing is an effective way to improve the friction behavior of polyimide composites and then correspondingly enhance the energy conversion efficiency and output performance of the traveling wave rotary ultrasonic motor.

Effect of Surface Texturing on Cast Iron Reciprocating against Steel under Cyclic Loading in Boundary and Mixed Lubrication Conditions

This study investigates the effect of laser surface texturing on the friction behavior of grey cast iron reciprocating under boundary, mixed lubrication conditions and cyclic loading. Four geometrical parameters of micro-textures (feature depth, feature diameter, area fraction, and sliding direction) were studied using a design of experiments (DoE) approach. The results showed that depending on the geometry, micro-textures can have either a positive or a negative effect on the friction behavior. The DoE analysis revealed that the coefficient of friction is mainly affected by the interaction of the feature depth and its diameter. It was found that this can be related to the aspect ratio of the dimples, and the best results were obtained for an aspect ratio of 0.1 and 0.17.

Tribological effects of laser surface texturing and residual stress

PurposeThe purpose of this paper is to investigate the tribological effects of laser surface texturing (LST) and residual stress on functional surfaces.Design/methodology/approachThree different surface textures (circular dimple, elliptical dimple and groove) with two different textured area ratios (10 and 20 per cent) are designed and fabricated by a Picosecond Nd YAG Laser machine. The friction and wear performance of textured specimens is tested using a UMT-2 friction and wear testing machine in mixed lubrication.FindingsTest results show that elliptical dimples exhibit the best performance in wear resistance, circular dimples in friction reduction and grooves in stabilization of friction. The surfaces with larger textured area density exhibit better performance in both friction reduction and wear resistance. The improved performance of LST is the coupled effect of surface texture and residual stress.Originality/valueThe findings of this study may provide guidance for optimal design of functional surface textures in reciprocating sliding contacts under mixed or hydrodynamic lubrication, which can be used in automotive and other industrial applications.

Effect of laser surface texturing on primary stability and surface properties of zirconia implants

Abstract The aim of this study was to investigate the influence of different laser surface texturing parameters on static and dynamic coefficient of friction values of Yttria-tetragonal zirconia polycrystals (3Y-TZP) against bone to assess the primary stability of implants. The ability of the textures to promote osseointegration, as measured by wettability, and eventual changes in roughness, due to possible aging during sterilization, were also assessed. 3Y-TZP disks were divided into four groups: as sintered sample, sandblasting and etching treatment, laser irradiation using two output power of 0.9 and 1.8 W. The friction tests were carried out by using a pin-on-plate configuration, being the pins the 3Y-TZP disks and the plates the bone. The surfaces were inspected by SEM/EDS and by surface roughness profilometer. Wettability characteristics were also evaluated by drop contact angle, and aging was assessed, after laser treatments, by XRD analysis. Results demonstrate that with laser surface texturing of zirconia it is possible to combine better wettability, better aging performance, and better primary stability, as compared to traditional - Sand blasting and Etching treatments. Thus, it is shown that the laser irradiation technique is a promising alternative to conventional sandblasting and etching procedures.

Effects of laser surface texturing on the wear and failure mechanism of grey cast iron reciprocating against steel under starved lubrication conditions

The purpose of this work was to investigate the effects of different texture patterns and orientations on the wear and failure mechanisms of grey cast iron sliding against 42CrMo6 steel. Reciprocating tests were performed on 16 different micro-textures under starved lubrication conditions. The textures were designed using a design of experiments (DoE) approach and produced by a nanosecond-laser. Under starved lubrication conditions, the non-textured samples always failed catastrophically by scuffing, which is a sudden and catastrophic failure. However, textured samples showed two different wear and failure mechanisms. It is revealed that the sudden and catastrophic failure due to scuffing can be avoided by surface texturing. Choosing the right distance between the micro-textures can change the surface damage mode from scuffing to a more gradual oxidative wear mechanism. For the studied tribo-system, it was shown that if the distance of micro-textures in the direction of sliding (DMS) is less than 3 mm, samples will fail by an oxidation mechanism. For textured samples with DMS greater than 3.5mm, the failure mechanism is scuffing, the same as for the non-textured cast iron.