Groove-textured Surfaces Research Articles

Study of the Friction Behavior of Embedded Fibers in YG8 Surface Grooves.

YG8 is a common cemented carbide material with excellent mechanical properties and mechanical properties, so it is widely used in the actual industry. However, due to the active chemical properties and strong affinity of tungsten alloy steel, it is easy to produce bonding and peeling in application, resulting in an unstable process and short service life. In order to control and reduce the surface wear of YG8 cemented carbide, groove-textured surface (GS) and flocking surface (FS) were prepared on smooth surface (SS). The friction characteristics of the samples were studied under different applied load conditions. The results show that the average friction coefficient of SS, GS and FS is inversely proportional to the load in dry/oil environment. Compared with SS, FS exhibits the lowest friction coefficient, which is reduced by 30.78% (dry friction) and 13.13% (oil lubrication). FS effectively improves the tooth jump phenomenon of the sample and the amplitude of the friction coefficient, friction force and load, and has the best anti-friction characteristics. At the same time, the FS with the fastest contact angle drop at any time also showed excellent wetting ability, and the wear rate decreased by an order of magnitude. The implantation of fibers in the groove inhibits the spalling and furrow of wear track, which is attributed to the effect of fibers on damage repair. In the friction process, FS increases the content of the O element and induces the formation of oxides. The friction mechanism is mainly chemical wear. The excellent tribological properties of FS have a good guiding significance and theoretical support for improving the tribological properties of high hardness material surfaces.

Improvement of current-carrying tribological behaviour via laser surface texture

ABSTRACT Three kinds of laser surface texture (LST), i.e. square pit-textured surface (SPTS), round pit-textured surface (RPTS) and groove-textured surface (GTS), are fabricated on the flat brass (H65) sample surfaces. The current-carrying tribological behaviour of these surfaces are investigated. It is noticed the COFs of smooth surface, SPTS and RPTS are all greater than 0.6 after the test, while the GTS has the lowest COF, which remains around 0.2 throughout the test. The vibration signals detected from all surfaces indicate the larger COF will not trigger the FIV generation in this state. All the texture surfaces will not cause electrical contact breaks. Worn surface analysis indicates the wear level of GTS is the weakest, with slight damage and debris accumulation occurs along the groove edges. Finite element analysis is performed to calculate the variation of contact force, contact temperature and voltage signal, and the test results can be well explained.

Tribological response of groove-textured surface with compressive stress on Ti6Al4V processed by laser and abrasive belt

Both texturing and residual stress have a positive effect on tribological properties of surface. According to the effect, a synergistic processing method by laser and abrasive belt is proposed. The results show that the texture of co-processed surface is more regular and flatter with stronger grooves retention. With none stress and initial stress as the benchmark, the co-processed surfaces are all in compressive stress. The co-processed surfaces exhibit some advantages under dry friction and boundary lubrication. When residual compressive stress is greater than the initial, the surfaces show better wear resistance where wear depth can be reduced by 56.88 % from 2.69 mm to 1.16 mm and wear area width can be reduced by 44.90 % from 689.41 mm to 379.84 mm.

Effect of Different Laser Groove Texture Collation Frequency on Tribological Properties of 0Cr17Ni7Al Stainless Steel.

Laser surface texture is very effective in antifriction systems, but its applications and research in dry friction are not enough. In this study, the groove texture was prepared on the surface of 0Cr17Ni7Al stainless steel, a common material of sliding bearing, by nanosecond and femtosecond laser, respectively. The tribological properties of the two kinds of laser groove textures with different collision frequencies were studied in depth. The results show that the friction coefficients of groove texture prepared by nanosecond and picosecond lasers are lower than that of the untextured surface. The antifriction characteristics of the laser texture are very good. The average friction coefficient of nanosecond texture at the rotation radius of 15 mm is Z = 0.7318. The best friction-reducing effect is achieved. In general, the friction coefficient of nanosecond texture is lower than that of picosecond texture. When the friction radius is 22.5 mm and the number of collisions is 24,000, the lowest picosecond texture wear rate is H = 3.342 × 10−4 mm3/N·mm. However, when the radius is 15 mm and the collision frequency is 36,000 times, the wear rate of nanosecond texture reaches the highest H = 13.680 × 10−4 mm3/N·mm. The wear rate of the untextured surface has been exceeded. It can be seen that not all rotation radius textures are more wear-resistant than untextured surfaces. In addition, nanosecond groove texture and picosecond groove texture seem to produce different tribological properties. It is found that, under the same friction experimental conditions, different collision frequencies will affect the friction and wear properties of nanosecond and picosecond groove-textured surfaces.

The synergetic effects of laser texturing and super-hydrophobic coatings on improving wear properties of steel

To investigate the synergetic effects of laser texturing and super-hydrophobic coatings on tribological performances, we prepare micro-grooves on steel substrates by femtosecond laser and then deposit super-hydrophobic coatings in the micro-grooves to obtain coated groove-textured surfaces (CGSs). The tribological behaviors of polished steel surfaces (PSSs), groove-textured surfaces (GSs), and CGSs under water lubrication are examined. Compared with PSSs and GSs, CGSs show significant anti-friction and wear-resisting properties under a relatively low load. With increasing the texture density, the wear resistance of CGSs decreases. When a load of 0.5 N is applied on the CGSs with a texture density of 10%, the friction coefficient and wear loss are reduced by 22.3% and 73.5%, respectively, compared with PSSs.

Projection Method for Droplet Dynamics on Groove-Textured Surface with Merging and Splitting

The geometric motion of small droplets placed on an impermeable textured substrate is mainly driven by the capillary effect, the competition among surface tensions of three phases at the moving contact lines, and the impermeable substrate obstacle. After introducing an infinite dimensional manifold with an admissible tangent space on the boundary of the manifold, by Onsager's principle for an obstacle problem, we derive the associated parabolic variational inequalities. These variational inequalities can be used to simulate the contact line dynamics with unavoidable merging and splitting of droplets due to the impermeable obstacle. To efficiently solve the parabolic variational inequality, we propose an unconditional stable explicit boundary updating scheme coupled with a projection method. The explicit boundary updating efficiently decouples the computation of the motion by mean curvature of the capillary surface and the moving contact lines. Meanwhile, the projection step efficiently splits the difficulties brought by the obstacle and the motion by mean curvature of the capillary surface. Furthermore, we prove the unconditional stability of the scheme and present an accuracy check. The convergence of the proposed scheme is also proved using a nonlinear Trotter-Kato's product formula under the pinning contact line assumption. After incorporating the phase transition information at splitting points, several challenging examples including splitting and merging of droplets are demonstrated.

Numerical simulation of hydrodynamic lubrication performance for continuous groove-textured surface

The numerical models of continuous groove textures with the characteristics of “X”-shaped units have been established. The effect of geometric parameters and sliding speed on tribological properties were systematically investigated. The optimal geometric parameters of each texture shape were determined. It is found that the circular texture shows the best lubrication performance at lower area densities. When the area density exceeds 25%, the square texture with the orientation of θ = 90° exhibits better tribological performance than the circular texture by increasing the groove depth. The lubrication mechanism is explained by the trade-off between the fluid flow and the generation of hydrodynamic pressure.

Effects of groove-textured surfaces filled with Sn-Ag-Cu and MXene-Ti3C2 composite lubricants on tribological properties of CSS-42L bearing steel

To improve the tribological performance of CSS-42L bearing steel, smooth surfaces (SSs), groove-textured surfaces (GSs), GSs with Sn-Ag-Cu (GSs-SAC), and GSs with Sn-Ag-Cu-Ti3C2 (GSs-SACT) were prepared on CSS-42L. In addition, experimental studies were conducted on tribological properties. The obtained results indicated that GSs-SACT exhibited the best anti-friction and noise reduction performances. These remarkable tribological performances were attributed to the synergistic effects of grooves, Sn-Ag-Cu, and MXene-Ti3C2. The inconsistent rules of frictional forces were improved by the grooves and SACT, which inhibit the friction-induced noise. The micro-nano size-effects of MXene-Ti3C2 enhanced the repairing effect and anti-friction property of composite lubricants, which improved the profile characteristics of GSs-SACT.

Effects of groove-textured surfaces with Sn-Ag-Cu and MXene-Ti3C2 on tribological performance of CSS-42L bearing steel in solid-liquid composite lubrication system

To expand the applications of MXene-Ti3C2 in solid-liquid lubrication system, CSS-42L smooth surfaces (SSs), groove surfaces (GSs), groove with Sn-Ag-Cu composite surfaces (GSs-SAC) and groove with Sn-Ag-Cu-Ti3C2 composite surfaces (GSs-SACT) are prepared. The tribological behaviors of samples under dry friction and oil lubrication are studied. The results show that Sn-Ag-Cu-Ti3C2 has the excellent oil film adsorption capacity. The micro-hydrodynamic effects of oil in the grooves are produced under oil lubrication. The synergistic effects of oil, Sn-Ag-Cu-Ti3C2 and grooves reduce the fluctuation amplitudes of friction force and load, improving bearing capacity of oil film and profile characteristics on the surfaces. GSs-SACT with uniform and smooth profiles shows the tribochemical wear and obtains the excellent antifriction and wear resistance properties.

Improved Load-Bearing Capacity and Tribological Properties of PTFE Coatings Induced by Surface Texturing and the Addition of GO

The PTFE coatings with excellent corrosion-resistance and lubrication properties often stop functioning under high load conditions. In this study, a composite coating of PTFE filled with silane coupling agent modified graphene oxide (mGO/PTFE) was prepared by a simple spin-coating process on textured stainless steel (SS) substrate to protect the substrate from failure under high load rubbing. The grafting reaction between GO and silane coupling agent was analyzed by FTIR, Raman, XRD, TGA, and XPS. The morphologies and tribological properties of the mGO/PTFE coatings on the untextured and textured SS substrates were characterized by SEM and UMT tribometer. The results showed that GO surfaces were successfully grafted by silane coupling agent, resulting in that the composite coating of mGO/PTFE was denser than the pure PTFE coating. The tribo-test results confirmed that the groove texture processed by laser surface texture technology greatly improved the load-bearing capacity and anti-wear life of the PTFE coatings. The PTFE coating on the untextured SS surface fails within half an hour of rubbing at the applied load of 10 N, while the one on the groove-textured surface can maintain low and stable friction coefficient for a long time even under the load of 50 N. In addition, the results showed that the loading of mGO further improve the friction reduction and wear resistance of the PTFE coating on the textured SS surface. The wear scar width and the friction coefficient are significantly reduced by 70% and 30%, respectively, as the PTFE coating was filled by 1.0 wt% mGO. Finally, the mechanisms for achieving outstanding properties of the composite coating of mGO/PTFE on the textured SS surface were illustrated by analyzing the wear surfaces of the coating and the counterpart balls by SEM and EDS.

In vitro cytocompatibility of a Zr-based metallic glass modified by laser surface texturing for potential implant applications

Existing studies have shown the benefit of laser surface texturing (LST) in promoting the cytocompatibility of traditional metallic biomaterials. Researchers have also reported the potential of bulk metallic glasses (BMGs) as an alternative class of material for biomedical applications. However, investigations specifically focussed on studying the cytocompatibility of BMG surfaces processed with LST are still lacking. The present work demonstrated the feasibility of nanosecond LST as a method to modify the cytocompatibility of a Zr-based BMG material known as Vitreloy 105. Two different types of laser-induced surface patterns, namely grooves and dimples, were considered. Their respective influence on the resulting cell viability, attachment and morphology was studied and compared against the cytocompatibility of the original BMG surface. It was found that MG63 osteoblast-like cells on the groove-textured surface exhibited higher viability and better adhesion compared to those on the original and dimple-textured surfaces. Possible underlying mechanisms associated with LST, which can affect the in vitro cytocompatibility of Vitreloy 105 were discussed based on the induced changes to surface chemistry, wettability and roughness. It is suggested that the higher surface roughness, increased presence of metallic oxides and enhanced hydrophilicity of the groove-textured sample were the main contributors to its improved cytocompatibility.

Improving Tribological Performance of Inconel 625 by Combining Groove-Textured Surfaces with Sn-Ag-Cu Solid Lubricant

High wear is the primary failure mechanism of Inconel 625 in mechanical parts. The surface modification is workable method to improve tribological performance of Inconel 625. In this paper, the groove-textured surfaces with different widths and pitches were prepared on the surfaces of Inconel 625 by electrical discharge machining technology. The Sn-Ag-Cu solid lubricant was deposited on the grooves. The synergistic effects of Sn-Ag-Cu solid lubricant and groove-textured surface on the tribological performance of Inconel 625 were studied. Results show that the groove-textured surface of Inconel 625 filled with Sn-Ag-Cu solid lubricant shows the lowest friction. Compared with the untextured sample, the friction coefficients of groove-textured sample with the groove density of 20% and the groove-textured sample with the groove density of 25% filled by Sn-Ag-Cu are reduced 35% and 48%, respectively. The textures can trap wear debris under the dry sliding condition. In addition, Sn-Ag-Cu alloys filled in the grooves supply the sufficient lubricant at the contact interface during the sliding process. The lubricating film on the contact surface is formed gradually, which is mainly due to the shear adaptability and low melting point of Sn-Ag-Cu alloy. It shows that deposition of Sn-Ag-Cu solid lubricant coating on the groove-textured surface is an effective way for improving the friction and wear performance of Inconel 625.

Effect of Substrate Surface Texture Shapes on the Adhesion of Plasma-Sprayed Ni-Based Coatings

The bonding of thermal-sprayed coatings largely depends on the substrate surface morphology. This study examines the effect of the substrate surface texture shapes on the adhesion strength of coatings. For that, it used plasma-sprayed Ni-based MoS2 coatings deposited on grit-blasted and laser-textured surfaces, and investigated the coating bonding strength (ASTM 633 pull-off test), and cross-sectional and fracture morphologies, as well as phase compositions and element distribution. The results showed that the surface texture shape has a significant effect on the improvement of coating adhesion. The coatings deposited on sinusoidal-textured surfaces had the highest adhesion strength (50.0 MPa), followed by coatings deposited on groove-textured surfaces, while dimple and dimple–groove textures resulted in the lowest coating adhesion strength. The coating fracture analysis revealed that cohesive failure occurred mainly at the texture positions, while adhesive failure occurred almost always in plain areas. Therefore, it could be concluded that, in the conditions of this study, the existence of plain areas and dimple textures did not improve coating adhesion. Factors such as coating bond mode, contact area ratio, and coating deposition quality should be comprehensively considered in texture design to improve coating adhesion.

Effects of groove-textured surface combined with Sn–Ag–Cu lubricant on friction-induced vibration and noise of GCr15 bearing steel

Taking GCr15 steel as the research object, the groove-textured surfaces (GTSs) and the composite antifriction surfaces (CASs) with the grooves and Sn–Ag–Cu were prepared. Experimental researches on the tribological performance, friction-induced vibration and noise of SS (smooth surface), GTSs and CASs were conducted. The results showed that SS exhibited the obviously abrasive wear characteristics, thus the uneven surface was obtained, leading to the high-frequency scream. The fluctuation of friction force caused by the grooves on GTSs could suppress the high-frequency scream but cause the low-frequency chatter. The cooperate effect of grooves and Sn–Ag–Cu increased the fluctuation amplitude of friction force, hence CASs profile with obvious wrinkles was formed, suppressing the friction-induced vibration and noise.

Effects of single- and multi-shape laser-textured surfaces on tribological properties under dry friction

Textural morphology is an important factor influencing dry friction, and few studies have been conducted regarding the effects of single- and multi-shape textures on dry tribological properties. In this work, six types of textures including single- and multi-shape textures were produced on 40Cr steel samples by using a nanosecond laser. Reciprocating sliding tests under dry friction were conducted using a pin-on-disc friction tester. The influences of textured surfaces with different textures on tribological properties were investigated. Results showed that tribological properties were affected by different textural morphologies. The dimple-textured surface had the highest friction coefficient, followed by the groove-textured surface. The sinusoidal-textured surface had the lowest friction coefficient. The friction coefficients of multi-shape textured surfaces were lower than those of non-textured surfaces but higher than those of sinusoidal-textured surfaces. The wear properties of the tested surfaces were consistent with the friction-coefficient results. The sinusoidal- and sinusoidal–groove-textured surfaces can be considered as the optimum choices for dry reciprocating friction.

Investigation of tribological performance of micro-groove textured cemented carbide surfaces

ABSTRACT Three kinds of grooved textures with different geometric patterns were prepared on cemented carbide tool surfaces. Finite element software FLUENT was used to simulate and analyse the fluid pressure of lubricants on the different micro-groove textured surfaces. Friction and wear experiments of titanium alloy balls and cemented carbides were carried out to investigate the tribological properties. The results show that the friction coefficient of the line groove textured surface is the smallest under dry friction conditions. Moreover, the friction coefficient of the sinusoidal groove textured surface is the smallest under fluid lubricated conditions. Experimental results show that lubrication of the grooved textured surfaces is consistent with the numerical simulation results. The main friction reduction mechanism of textures involves reducing the contact area of friction pairs and capturing debris under unlubricated conditions and supplying lubrication to form a continuous lubrication film and producing a dynamic pressure effect under fluid lubricated conditions.

Effect of texture parameters on the tribological properties of spheroidal graphite cast iron groove-textured surface under sand-containing oil lubrication conditions

During the process of fabricating sand cores with a sand-moulding machine, silica sand can become embedded in the sliding guideway, causing serious abrasive wear. To improve the tribological performance of the sliding guideway, groove textures were fabricated on the spheroidal graphite cast iron surface to capture the silica sand. It was found that the friction coefficient of the groove-textured surface (depth, h, of 0.05 mm; width, w, of 1.5 mm; area density, Sp, of 34%) was 12.7% lower than that of the non-textured surface under oil lubrication. Meanwhile, the groove-textured surface achieved excellent wear resistance performance with groove parameters of h ≥ 0.40 mm, w ≥ 1.0 mm, and Sp ≥ 34%. The wear resistance of the textured surface (h = 0.40 mm, w = 1.5 mm, and Sp = 34%) was 4.9 times greater than that of the non-textured surface. The main wear mechanism of the groove-textured surface with a high depth, width, and area density was slight abrasive wear or scratching under the given test conditions, which was attributed to the larger groove trapping the sand so that less sand remains on the substrate.

Study on the Correlation Between Dynamical Behavior and Friction/Wear Mechanism Under the Effect of Grooves

In this work, the interfacial friction and wear and vibration characteristics are studied by sliding a chromium bearing steel ball (AISI 52100) over both multi-grooved and single-grooved forged steel disks (20CrMnMo) at low and high rotating speeds in order to reveal the effect mechanism of groove-textured surface on tribological behaviors. The results show that the grooves modify the contact state of the ball and the disk at the contact interface. This consequently causes variations in the normal displacement, normal force, and friction force signals. The changes in these three signals become more pronounced with increasing groove width at a low speed. The collision behavior between the ball and the groove increase the amplitude of vibration acceleration at a high speed. The test results suggest that grooves with appropriate widths could trap wear debris on the ball surface while avoiding a strong collision between the disk and the ball, resulting in an improvement in the wear states.

Debris trapping and space-varying contact via surface texturing for enhanced noise performance

In this work, groove-textured surfaces with a certain widths and pitches are manufactured on flat cast iron samples. Whereafter, another material (aluminium and steel, respectively) is filled into the grooves to form a special surface which possesses space-varying properties. These surface-treated specimens are tested in a ball-on-flat system and the ensuring friction-induced vibration and noise are measured. The ball sample used in the test is chromium bearing steel ball (AISI 52100). It is found that adding aluminium material into the grooves will increase the friction-induced vibration and noise level of friction system. Conversely, adding steel material into the grooves can stabilize the friction system. Moreover, this space-varying contact state surface is valuable to study the relationship between the trapping wear debris behaviour and stability of texturing surface, which validates our previous speculation that wear debris accumulation on the contact surface will deteriorate the friction-induced vibration and noise behaviour of friction system, and the capability of grooves in trapping wear debris is beneficial for reduction of vibration and noise. Numerical simulation is performed to give reasonable explanations for the experimental phenomenon. This investigation suggests that friction surfaces with grooves filled with suitable materials are able to reduce friction-induced vibration and noise.

Effect of groove surface on friction noise and its mechanism

In this study, friction noise according to whether grooves exist was measured using a reciprocating sliding device, and the relationship between the groove and friction noise mechanism was investigated. Experimental results revealed that both non-groove textured and groove textured surfaces produced friction noise at approximately 5 kHz. However, the friction noise onset time was relatively faster and the sound pressure level was higher for the non groove textured surface. The tribo-surfaces of the plate and ball which change in time for the non-groove textured and groove textured surfaces were observed using a microscope. For the non-groove textured surface, adhesive wear was commonly observed on the tribo-surface, and for the groove textured surface, wear particles accumulated within the groove due to the movement of the ball, and adhesive wear appeared more slowly. As a result, the friction coefficient was relatively larger for the non-groove textured surface, facilitating the mode coupling instability. Using the pin-on-disk system, the propensity for the negative friction-velocity slope was also measured with regard to the non-groove textured surface.