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The main purpose of this study is to enhance bio-tribological properties of Ti6Al4V and the surface-modified layers of Ni⁺/N⁺-implanted Ti6Al4V alloy, bionic texturing was done on Ti6Al4V surface.

The phase compositions and nano-hardness of the surface-modified layers of the samples have been analyzed by X-ray diffractometer and Nano Indenter, respectively. This paper has conducted bio-tribological tests under artificial saliva, sodium hyalurate and sodium hyalurate +γ-globulin by micro tribology multifunction tribometer, with ZrO2 ball/modified layer as the friction pair. S-3000N scanning electron microscope has been used to analyze the morphology of the surface-modified layers and scratches of the ones after the bio-tribological tests.

The results show that the surface-modified layers were mainly composed of Ti₂Ni and Ti₂N. Moreover, bionic texturing can obviously increase the contents of Ti₂Ni and Ti₂N that were formed on the surface of Ni⁺/N⁺-implanted Ti6Al4V alloy, and enhance the nano-hardness of the surface-modified layers. It could also reduce the friction coefficients of the surface-modified layers, and render the modified layers more wear-resistant.

The surface bio-tribological properties of Ti6Al4V have been enhanced by ion implantation technique and bionic texturing in this paper; this provided a new method for the research of related fields.

Gears are prone to instantaneous failure when operating under extreme conditions, affecting the machinery’s service life. With numerous types of gear meshing and complex operating conditions, this study focuses on the gear–rack mechanism. This study aims to analyze the effects and optimization of biomimetic texture parameters on the line contact tribological behavior of gear–rack mechanisms under starvation lubrication conditions.

Inspired by the microstructure of shark skin surface, a diamond-shaped biomimetic texture was designed to improve the tribological performance of gear–rack mechanism under starved lubrication conditions. The line contact meshing process of gear–rack mechanisms under lubrication-deficient conditions was simulated by using a block-on-ring test. Using the response surface method, this paper analyzed the effects of bionic texture parameters (width, depth and spacing) on the tribological performance (friction coefficient and wear amount) of tested samples under line contact and starved lubrication conditions.

The experimental results show an optimal proportional relationship between the texture parameters, which made the tribological performance of the tested samples the best. The texture parameters were optimized by using the main objective function method, and the preferred combination of parameters was a width of 69 µm, depth of 24 µm and spacing of 1,162 µm.

The research results have practical guiding significance for designing line contact motion pairs surface texture and provide a theoretical basis for optimizing line contact motion pairs tribological performance under extreme working conditions.

The purpose of this paper is to study the influence of dimple textures on the friction and wear properties of tapered roller bearings (TRBs) with many pattern parameters, e.g. diameter, depth and area density under starved lubrication.

The pattern parameters include the dimple diameter (D; 60, 100 and 200 µm), dimple depth (H; 5, 10 and 20 µm) and area density (S; 6%, 12% and 24%). Dimples were fabricated on the outer ring (OR) of TRBs using a laser marking machine. The tribological properties of dimple-textured TRBs under starved lubrication were studied on a vertical universal friction wear tester with special friction pairs. The effect mechanisms of dimple textures on the tribological properties of TRBs are presented and summarized through experiments and discussions.

When dimple-textured TRBs revolve under starved lubrication, the average coefficients of friction (ACOF) and wear losses are markedly lower than those of non-textured bearings. S has the greatest influence on the COF curve. When D is 100 µm and S is 24%, the ACOF and wear losses are both lowest, i.e. 0.00426 and 0.51 mg, respectively. Under the same test conditions, compared with the non-textured group, its COF and wear loss decreased by 35.6% and 62.5%, respectively.

This work provides a useful reference for the research on the raceways of textured TRBs.

The purpose of this study is to elucidate the size effect (groove width, unit length and area density) of the hexagonal texture on tribological properties under lubrication.

The tribological properties of nine hexagonal textures with different hexagon lengths and groove widths have been investigated under mixed lubrication to elucidate the size effect.

Overall, the friction coefficient decreases as the groove width increases within the examined range, whereas the hexagon length shows an optimal value around 3 mm. In particular, one hexagonal texture (3 × 3 mm) exhibits lower friction coefficients and less wear losses than the others. Interestingly, two hexagonal textures of similar area density (1 × 1 mm and 3 × 3 mm) yield the worst and best tribological performances, respectively, which can be explained by the simulated distribution of equivalent stress.

The tribological properties of nine hexagonal textures are examined under lubrication. The 3 × 3 texture exhibits lower friction coefficient and wear loss than the others. Two textures of similar area density yield the worst and best tribological performances. The results agree with the simulated distribution of equivalent stress.

The purpose of this paper is to design a kind of air bearing which is based on bionics. Compare with ordinary air bearing, the air pressure consumption is reduced and energy is saved.

This paper puts forward a proposition that a bionic bearing structure is designed based on the bionics principle. First, the authors analyze the microstructure of the wings of long-eared owls and the structural mapping model is established. Second, the theoretical formula is derived through the model, and the structural parameters are optimized by sequence quadratic program (SQP). Lastly, the experimental model is made by 3D printing technology, and the experimental data are analyzed to verify the feasibility of the theory.

By comparing the experimental data, it can be seen that the air pressure of the original air bearing is reduced by 27 per cent, and the validity of the theory and design method is verified.

In this paper, a design method of air bearing based on bionic principle is presented, which can save the air pressure required for working of air bearing, and the structure of air bearing is expected to be applied in engineering.

This study aims to find the dynamic performance parameters of the journal bearing with micro geometries patterning the arc (crescent) shape textures provided in three specific regions of the journal bearing: the full, the second half and the increasing pressure region. The dynamic behavior of textured journal bearings has been analyzed by computing dynamic parameters and linear and non-linear trajectories.

The lubricant flows between the bearing and journal surface are governed by Reynold’s equation, which has been solved by finite the element method. The dynamic performance parameters such as stiffness, damping, threshold speed, critical mass and whirl frequency ratio are examined under various operating conditions by considering various ranges of eccentricity ratios and texture depths. Linear and non-linear equations of motion have been solved with Ranga–Kutta method to get journal motion trajectories. Also, the impact of adding aluminum oxide and copper oxide nanoparticles to the base lubricant in combination with arc-shaped textures is analyzed to further see any enhancement in the performance parameters.

The findings demonstrated that direct stiffness and damping parameters increased to their maximum level with six textures in the pressure-increasing region when compared with the untextured surface. Also, nanoparticle additives showed improvements above the highest value attained with no inclusion of additives in the same region or quantity of textures.

Engineers may design bearings with improved stability and overall performance if they understand how texture form impacts dynamic properties.

The purpose of this paper is to investigate the effects of different surface structures, dimensional parameters and cavitation models on the lubrication characteristics of water-lubricated journal bearings.

In this paper, the coupling iteration method of ANSYS and MATLAB is established to calculate the journal orbits of water-lubricated bearing, and the differences between the journal orbits of the smoothed and the textured water-lubricated bearings are compared and analyzed, and the effects of different bearing materials, L/D ratios and clearance ratios on the lubrication performance of water-lubricated bearings are investigated. The effects of different cavitation models on the static equilibrium position and whirling trajectory of water-lubricated bearings are compared.

The results show that when the surface texture is distributed in the upper bearing or the bearing elastic modulus decreases, the bearing stability increases. Considering shear cavitation and noncondensing gas, the rotor journal orbits amplitude decreases at high speed with low clearance ratio. A water film test rig for water-lubricated bearings is built to measure the full-circle water film pressure of water-lubricated journal bearings, and the experimental results are compared with the simulation results, which are in good agreement.

The findings provide a theoretical basis for optimizing the structure of water-lubricated bearings.

This paper aims to investigate the tribological benefits of a biomimetic teardrop surface texture inspired by snakeskin compared to conventional surface textures with the help of geometrical and flow parameters using computational fluid dynamics techniques.

The lubricant is assumed to be Newtonian, and the flow is laminar with constant viscosity and isothermal property. The governing equations, continuity and Navier–Stokes equation, are discretised by the finite volume method, and cavitation modelling is included. The discretisation for the momentum equations is carried out using the second-order difference method for the SIMPLEC algorithm of pressure–velocity coupling.

The results indicate that biomimetic teardrop surface texturing performs better than conventional shapes surface textures in improving tribological performance. Furthermore, the parallel texture orientation along with the flow generates a high-pressure distribution relative to other orientations. Surface texture area density also highly influences the load-carrying capacity, which is optimum at 29%. Zigzag pattern arrangement performs better compared to linear pattern arrangement of texturing.

The paper proposes that this unique biomimetic teardrop shape can give better tribological performance than conventional shapes.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-02-2024-0053/

The purpose of this paper is to design a biomimetic surface structure for use in a glass transport device to enhance the suspension lift of a glass transport unit.

This paper presents a surface structure of a suspended glass transport device based on the principle of bionics. First, a mapping model is constructed based on the wing structure. Second, the optimal structural parameters are given according to genetic algorithm optimization. Finally, the experimental comparison of the test bench verified the feasibility of the theory.

Through experimental comparison, the biomimetic suspension glass transport device saves 20% of air pressure compared with the ordinary suspended glass transport device, which verifies the effectiveness of the theoretical method.

This paper proposes a suspended glass transport device based on the principle of bionics, which saves the air pressure required for work. It is expected to be used in suspension glass transport devices.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-09-2019-0389/

Micro-surface texturing is emerging as a possible way to enhance the tribological performance of hydrodynamic fluid film bearings. In view of this, numerical simulations are carried out to examine the influence of surface texture on performance of hybrid thrust bearing system. This paper aims to determine optimum attributes of micro-grooves for thrust bearing operating in hybrid mode.

An iterative source code based on finite element formulation of Reynolds equation has been developed to numerically simulate flow of lubricant through the bearing. Mass-conserving algorithm based on Jakobsson–Floberg–Olsson (JFO) condition has been used to numerically capture cavitation phenomenon in the bearing. Gauss Siedel method has been used to obtain steady state performance parameters of the bearings.

A parametric study has been performed to improve the load supporting capacity of the bearing by optimizing micro-groove attributes and configuration. It is noticed that use of full-section micro-groove is beneficial in improving the efficiency of bearing by enhancing the fluid film reaction and reducing the film frictional power losses.

This study is helpful in examining the usefulness of micro-groove textured surfaces in hybrid thrust bearing applications.