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The purpose of this paper is to investigate the effects of surface texture with roughness orientation considered on tribological properties under a mixed lubrication state numerically and experimentally.

Based on the average Reynolds equation and asperity contact model, the impacts of surface texture parameters and roughness orientation on lubrication properties have been calculated using finite difference method. Tin–bronze samples with various prescribed surface texture geometric parameters and roughness orientation were fabricated by laser surface texturing technique, and the tribology performance of the textured surface was studied experimentally.

The effects of surface geometric parameters and roughness orientation parameters have been discerned. The experimental observations are in good agreement with the numerical prediction, which suggests that the numerical scheme adopted in this work is suitable in capturing the surface texture and roughness effect under mixed lubrication state.

By meticulously controlling the surface roughness and surface texture geometric characteristics based on the laser surface texturing process, samples with prescribed surface texture parameters and roughness orientation consistent with that in theoretical studies were fabricated and the theoretical model and results were verified experimentally.

The purpose of this paper is to investigate the coupling mechanism of the roughness distribution characteristic and surface textures on the cylinder liner.

The cylinder liner-piston ring lubrication model with non-Gaussian roughness distribution surface was proposed in this paper to find the optimum cylinder liner surface. The motored engine tests were carried out to verify the simulation results.

The calculation and experiment results show that the large negative skewness surface has the optimal lubrication performance in the un-textured liner, while in the textured liner, the small negative skewness surface is more appropriate, which means surface textures couple with small negative skewness surface can improve the lubrication performance.

Although there are some works related to liner surface roughness and textures, the combine of roughness distribution and surface textures is not usually taken into account. Therefore, this research is different from others, as the present model considers with real non-Gaussian roughness distribution liners.

The developed plasto-elastohydrodynamic lubrication (PEHL) model is used to demonstrate the permanent change of macro morphology by critical high local stress at micro asperities in contact, which may further affect the fluid-film characteristics.

Geometric morphology is integrated into the PEHL model to elucidate the fluid-film properties governed by both macro- and micromorphologies.

Results show the model, accounting for combination of elastic and plastic deformations, realistically reveals fluid film distribution affected by the significant pressure highly concentrated within surface micro roughness interaction. The designed macroscopic textured surface mitigates the fluid film rupture phenomenon and prevents accumulated wear degradation from plastic deformation.

The PEHL model takes into account both elastic and plastic deformations and realistically reveals the fluid film distribution affected by large pressures that are highly concentrated in surface micro-roughness interactions. The macro-textured surfaces are designed to mitigate fluid film rupture phenomena and prevent cumulative wear caused by plastic deformation.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-05-2024-0170/

The purpose of this paper is to study the impact of different types of textures on the friction lubrication performance of cylindrical roller bearings.

In the present study, the composite texture hydrodynamic lubrication model that takes into account the effects of surface roughness is established, and the Reynolds equation for the oil film is numerically solved using the finite difference method. The study investigates the oil film carrying capacity and maximum pressure of bearings under two different arrangements of four composite textures and conducts a comparative analysis of the oil film characteristics under various texture parameters and surface roughness levels.

When the roughness of the inner texture surface and the contact surface are equal, the bearing capacity of the composite texture is intermediate between the two textures. The impact trend of surface roughness on fluid dynamic pressure effects varies with the type of composite texture; the internal roughness of the texture affects the micro-hydrodynamic pressure action. Composite textures with different depths exhibit improved bearing capacities; elliptical cylindrical parallel and elliptical hemispherical parallel textures perform better when their area densities are similar, while other types of composite textures show enhanced bearing performance as the ratio of their area densities increases.

This paper contributes to the theoretical investigations and analyses on designing the textured rolling bearings with high lubrication performance.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-02-2024-0050

This paper aims to obtain the film thickness, friction torque and pumping rate and analyze the effects of roughness and surface micro-dimple texture (circular, square and equilateral triangle) on the performance of the oil seal.

On the basis of elastohydrodynamic lubrication and the pumping mechanism of rotating shaft seal, this paper establishes a numerical model of hybrid lubrication of oil seal in sealing area. The model is coupled with fluid mechanics, rough peak contact mechanics and deformation analysis.

The results show that surface texture significantly improves the lubrication properties of the oil seal. The oil seal with the square texture has the largest oil film thickness, while the equilateral triangle texture has a better effect on the pumping rate.

To get closer to the real working environment of the oil seal, based on the surface roughness, this paper studies the effect of the texture shapes applied to the oil seal lip surface on the performance of the oil seal. The critical roughness and rotational speed values with zero pumping rate are obtained, which provides a theoretical basis for the correct selection of oil seals.

This study aims to enhance pedestrian safety by investigating the slip resistance of facility floors with ceramic tile surfaces and identifying critical surface roughness parameters that influence slip resistance.

Dynamic friction tests and comprehensive surface roughness analyses were conducted on ceramic tiles. Statistical analysis identified optimal roughness ranges for key parameters (R_a, R_p, R_t, R_z and R_v) to ensure the dynamic friction coefficient exceeds 0.5 to meet safety requirements. This study assessed different textures under dry, damp and foamy conditions.

The findings reveal that ceramic tile surfaces with higher peak heights and deeper valleys provide superior traction, particularly in damp and foamy conditions. The results demonstrate that specific surface textures can effectively mitigate slip and fall hazards by enhancing grip and increasing surface interaction points. This study establishes optimal roughness ranges for the critical parameters, providing a robust framework for improving slip resistance.

This study offers practical guidelines for designing safer ceramic tiles, emphasising the importance of tailored surface roughness to improve traction. It highlights the importance of considering environmental factors in slip resistance assessments, offering valuable insights for manufacturers, designers and policymakers. By focusing on specific surface textures, this study advances the development of safer built environments in public facilities. Future research directions should explore a broader range of tile finishes, footwear types and contaminant scenarios to refine the understanding of traction performance further.

This paper aims to present investigation on textured polyimide (PI) substrate for enhanced light absorption in flexible black silicon (bSi).

Flexible bSi with thickness of 60 µm is used in this work. To texture the PI substrate, copper-seeding technique is used. A copper (Cu) layer with a thickness of 100 nm is deposited on PI substrate by sputtering. The substrate is then annealed at 400°C in air ambient for different durations of 60, 90 and 120 min.

With 90 min of annealing, root mean square roughness as large as 130 nm, peak angle of 24° and angle distribution of up to 87° are obtained. With this texturing condition, the flexible bSi exhibits maximum potential short-circuit current density (J_max) of 40.33 mA/cm², or 0.45 mA/cm² higher compared to the flexible bSi on planar PI. The improvement is attributed to enhanced light scattering at the flexible bSi/textured PI interface. The findings from this work demonstrate that the optimization of the PI texturing via Cu-seeding process leads to an enhancement in the long wavelengths light absorption and potential J_max in the flexible bSi absorber.

Demonstrated enhanced light absorption and potential Jmax in flexible bSi on textured PI substrate (compared to planar PI substrate) by Cu-seeding with different annealing durations.

This paper aims to study the startup performance of thrust bearing. The effects of acceleration scenarios, roughness, the area ratio of texture and texture depth on the transient startup performance of the thrust bearing were analyzed.

The lubrication model is solved by the Reynolds equation with the mass-conservation boundary condition. The Greenwood and Tripp contact model is used to predict asperity contact load. The finite volume method is used to discretize the governing equations.

By studying the bearing performance with different acceleration functions, it was found that the higher the acceleration at the beginning of the startup, the faster the thrust bearing operates under the hydrodynamic lubrication regime in the start stage. It appears that the friction and contact time of asperity increase with the increasing roughness. The optimal area ratio of texture is within 30%–50%. The depth of texture ranging from 1 to 2 is the best.

This paper proposes a transient mixed lubrication analysis model of the thrust bearing. This model can be used to analyze the variations of tribological performance and lubrication regime of the thrust bearing under different acceleration scenarios.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-09-2022-0268/

The purpose of this paper is to machine the pressure surface of the turbine blade made of A286 iron-based superalloy by using four directions of raster strategy, including horizontal upward, horizontal downward, vertical upward and vertical downward, to achieve appropriate surface roughness and to investigate the tool wear in each strategy.

In this study, all cutting tests were performed by DAHLIH-MCV 1020 BA vertical 3-axis machining center with ball nose end mill. After milling by each strategy, according to the surface slope, the surface was divided into 27 meshes, and roughness of surface was studied and compared. Roughness measuring after machining was implemented by using portable Mahr ps1 roughness tester, and surface texture was photographed by CCD 100× optical zoom camera. Also, to measure tool flank wear in each strategy as an indication of tool life, the surface of workpiece was divided into four equal areas. The wear of the inserts was measured by ARCS vertical non-contact measuring system at the end of each area.

The results indicate that cutting directions and toolpath strategies have significant influence on tool wear and surface roughness in machining processes and that they can be taken into consideration individually as determinative parameters. In this case, the most uniform surface texture and the lowest surface roughness are obtained by using horizontal downward direction; in addition, abrasion is a dominant tool wear mechanism in all experiments, and tool wear in the horizontal downward is lower than other strategies.

Machining of turbine blades or other airfoil-shaped workpieces is quite common in manufacturing aerospace and aircraft products. The results of this research contribute to increasing quality of machined surface and tool life in machining of turbine blade.

This work proves the significance of milling strategies in machining of the turbine blade made of A286 superalloy and, consequently, exhibits the proper strategy in terms of surface roughness and tool life. Also, this work explains and elaborates the behavior of A286 superalloy in machining processes, which has not been studied much in recent research works.

During running-in, the change in the honed cylinder liner surface alters the performance and efficiency of the piston ring-pack system. The present paper, thus, aims to investigate the surface topography and wear and friction evolution of a cylinder liner surface during the running-in tests on a reciprocating ring–liner tribometer under a mixed lubrication regime. After an initial period of rapid wear termed “running-in wear”, a relatively long-term steady-state surface topography can emerge. A numerical model is developed to predict the frictional performance of a piston ring-pack system at the initial and steady-state stages.

The liner surfaces are produced by slide honing (SH) and plateau honing (PH). The bearing area parameter (Rk family), commonly used in the automotive industry, is used to quantitatively characterize the surface topography change during the running-in process. A wear volume-sensitive surface roughness parameter, Rktot, is used to show the wear evolution.

The experimental results show that a slide-honed surface leads to reduced wear, and it reduces the costly running-in period compared to the plateau-honed surface. The simulation results show that running-in is a beneficial wear process that leads to a reduced friction mean effective pressure at the steady-state.

To simulate the mixed lubrication performance of a ring–liner system with non-Gaussian roughness, a one-dimensional homogenized mixed lubrication model was established. The real surface topography instead of its statistical properties is taken into account.