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The purpose of this paper is to investigate the tribological effects of laser surface texturing (LST) and residual stress on functional surfaces.

Three 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.

Test 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.

The 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.

The purpose of this paper is to describe the tribological characteristics with different area density of concave-convex micro-texture on the mold surface. It is a new technology to improve the quality of the workpiece to control the tribological properties through the application of concave-convex micro-texture on the mold surface.

Five groups of laser micro-texture with different area density (ratio of the concave-convex micro-texture area to the all-area) were processed on the surface of the mold steel, and the tribological properties were compared with the smooth surface of the reference sample.

The time of the running-in stage in different experimental groups was about 300 s. The fluctuation amplitude of concave-convex micro-texture friction coefficient is much larger than that of smooth plane specimen in the running-in stage. After the running-in stage, the friction coefficients were lower than that in the smooth condition and decreased with the increase of the concave-convex micro-texture area density. When the area density reached 25%, the friction coefficients no longer decreased significantly. In addition, the wear of concave-convex micro-texture surface is much lower than that of smooth surface and decreases with the increase of concave-convex micro-texture area density.

Domestic and foreign scholars have done a lot of research on the relationship between concave micro-texture and tribological properties. However, the object of this paper is a new concave-convex micro-texture, which is rarely studied in the field of tribology.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-03-2020-0081/

Test the detail resolution of fused deposition modeling (FDM) in the direct manufacture of rapid prototypes with textured surfaces.

A benchmark part carrying regular surface patterns with different feature sizes and aspect ratios has been manufactured on a FDM system with different build orientations. Layered parts have been inspected to detect the occurrence of quality defects on textured surfaces.

The experiments reveal the ability of currently available FDM systems to enhance prototype surfaces with form details on a millimeter scale. Results assist in identifying conditions which need to be satisfied in order to successfully reproduce generic texture geometries.

Although the testing method can be applied to any layered manufacturing technique, results are limited to a specific process, and may be influenced by technical improvements of commercial fabrication systems.

A first contribution is given to a full feasibility assessment of direct texturing, which potentially appears as more responsive and cost‐effective solution than current post‐finishing practices.

The paper proposes a systematic approach to the manufacture of textured parts by rapid prototyping techniques. The analysis of surface appearance in the presence of small‐scale form details adds a novel aspect to current approaches to performance benchmarking, which typically focus on form errors and roughness of plain surfaces.

The purpose of this paper is to investigate and discuss the effect of multi-shape laser surface texturing (LST) steel surfaces on tribological performance.

The textured surface with some specific formula arrays was fabricated by laser ablation process by combining patterns of circles and triangles, circles and squares and circles and ellipses. The tribological test was performed by a flat-on-flat tribometer under dry and lubrication conditions, and results were compared with that of untextured surface.

The results showed that the textured surface had better friction coefficient performance than the untextured surface due to hydrodynamic lubrication effect. Through an increase in sliding speed, the beneficial effect of LST performance was achieved under dry and lubrication conditions.

This paper develops multi-shape LST steel surfaces for improving the friction and wear performance under dry and lubrication conditions.

The purpose of this paper is to study the pumping efficiency of oil seals with different surface textures at different speeds, and the influence of the rotation direction of triangular texture on the sealing performance was further analyzed.

Based on the theory of elastohydrodynamic lubrication and the pumping mechanism of rotary shaft seals, establishing a numerical model of mixed lubrication in oil seal sealing area. The model is coupled with the lip surface texture parameters and the two-dimensional average Reynolds equation considering the surface roughness.

The results show that the application of lip surface texture technology has obvious influence on the oil film thickness, friction torque and pumping rate of oil seal. The triangular texture has the most significant effect on the increase of pump suction rate. When the rotation direction of triangular texture is 315 degrees, the pumping rate of oil seal is the largest compared with the other seven directions.

The model has a comprehensive theoretical guidance for the design of new oil seal products, which provides a certain basis for the application of surface texture technology in the field of sealing in the future.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-06-2020-0198/

This paper aims to improve the wear resistance of metal rubber microfilaments and the service life. The effect of surface texture by laser processing on the fretting friction properties of metal rubber microfilaments was studied.

The LQL-F20A laser marking machine was used to fabricate a ring groove array with equal spacing and dense arrangement on the surface of metal rubber microfilaments. The test was carried out with a self-made micro-dynamic frictional tester. The topography of the microfilaments was observed by scanning electron microscopy and analyzed.

It has shown that laser surface texturing can improve the wear performance of microfilaments. Under the same experimental conditions, the microfilaments of textured surface has a smaller depth of wear than un-textured specimen. The wear resistance increases with the increase of texture density. The friction coefficient of textured specimen is significantly reduced compared with un-textured specimen, and the surface texture density of microfilaments has little influence on the friction coefficient after stabilization. In the stage of stable fretting wear, the wear depth will be more with the increase of the load.

There is little research on metal rubber microfilaments tribological properties. In this paper, the effect of laser texturing of microfilaments on micro-dynamic friction properties was studied by friction machine to provide a reference for the application of metal rubber in aerospace, medical and other fields.

Surface texturing has emerged in the past two decades as a viable option of surface engineering, resulting in significant improvement in wear resistance and friction coefficient. The purpose of this study is to find the appropriate surface texture to reduce vibration and improve the stability of journal bearings.

Micro-dimples, evenly distributed in a square array, were selected as the texture pattern and formed on the lower surface of bush by the laser surface texturing technique. Experiments were carried out to evaluate the effects of micro-dimples under different depths, densities and distributions.

The results are summarized in the form of shaft center orbits, waterfall illustrations and Hilbert-Huang transforms. In the entire test, it was found that an optimum geometric and distributive range of micro-dimples exists, where vibration acceleration can be decreased at least 3dB and stability can be greatly improved.

A majority of researchers devoted to studying on static characteristics, such as friction coefficient, load carrying capacity, pressure distribution and cavitation model. Besides, the influence of surface texture on stability of rotor-journal bearing system was rarely investigated and the recent examples can be found in Refs. (Ausas et al. 2007). However, a complete study of textured journal bearings has not been undertaken in the dynamic properties. Therefore, the purpose of this paper is to experimentally investigate the comprehensive effects of density, depth and distribution of micro-dimples on bearing vibration and stability.

Surface texturing can improve the tribological performance of contacting sliding surfaces under different contact and lubrication conditions, which has been proved both numerically and experimentally. This study aims to suggest a new methodology to evaluate the tribological behavior of textured surfaces using an adapted pendular scratch tester.

A Charpy-type tester was adapted to meet conditions that are relevant for sliding surfaces. The test rig was used to evaluate low carbon steel textured surfaces produced via maskless electrochemical texturing. The textures were composed of 100 pockets with an average diameter of 200 µm of and variable average depths (1.5, 3.5 and 7 µm). The tests were performed under dry and lubricated conditions for smooth and textured surfaces. The lubricated tests simulated a starved condition by applying a drop of lubricant.

For starved lubrication, surface texturing reduced the sliding energy when compared with smooth surfaces. This was attributed to the pocket’s ability to provide an additional supply of lubricant, as well as a reduced amount of plastic deformation around the pockets during sliding of the indenter. However, under dry sliding conditions, no significant effect of surface texturing was detected.

A new evaluation methodology was proposed, using single-pass pendular sliding of a spherical indenter to measures the energy absorbed during sliding, which was referred to as sliding energy. The measurements are repeatable and can detect sliding energy differences between smooth and textured surfaces.

The purpose of this paper is to investigate the effect of round pits arrangement patterns on tribological properties of journal bearing. In this paper, the tribological behaviors of journal bearing with different arrangement patterns under lubrication condition were studied based on M-2000 friction and wear tester.

The friction and wear of journal bearing contact surface were simulated by ANSYS. The wear mechanism of bearing contact surfaces was investigated by the means of energy dispersive spectrum analysis on the surface morphology and friction and wear status of the journal bearing specimens by Scanning Electron Microscopy (SEM) and Energy Dispersive Spectrometer (EDS). Besides, the wearing capacity of the textured bearing was predicted by using the GM (1,1) and Grey–Markov model.

As the loads increase, the friction coefficient of journal bearing specimens decrease first and then increase slowly. The higher rotation speed, the lower friction coefficient and the faster temperature build-up. The main friction method of the bearing sample is three-body friction. The existence of texture can effectively reduce friction and wear. In many arrangement patterns, the best is 4# bearing with round pits cross-arrangement pattern. Its texturing diameters are 60 µm and 125 µm, and the spacing and depth are 200 µm and 25 µm, respectively. In addition, the Grey–Markov model prediction result is more accurate and fit the experimental value better.

The friction and wear mechanism is helpful for scientific research and engineers to understand the tribological behaviors and engineering applications of textured bearing. The wear capacity of textured bearing is predicted by using the Grey–Markov model, which provides technical help and theoretical guidance for the service life and reliability of textured bearing.

The purpose of this paper was to carry out an experimental study to investigate tribodynamics at the interface of chrome steel pin with the plain and textured surface cast iron discs in a fully flooded condition.

A friction and wear tester (tribometer) was used for conducting the experiment at different operating parameters. Lubricating oil used in this experiment was SAE-15W40, which directly supplied at the interface and ensured a fully flooded lubricating condition. Measurements of different parameters, such as friction coefficient, the rate of wear, the amplitude of vibration, rise in temperature and intensity of sound, were considered at different loads. The input parameters were taken in a range viz. Loads from 1.9 MPa to 3.1 MPa, sliding speeds from 2 to 10 m/s and distance travelled ranged from 1000 to 5000 m.

In the investigation, it was found that there was a decrease in friction coefficient and wear rate at the interface formed by the chrome steel pin with textured surface cast iron disc when compared with friction coefficient and wear rate at the interface formed by the chrome steel pin and the plain surface disc of cast iron.

Also, it was inferred that temperature, vibration and noise level, at the interface formed by the chrome steel pin and plain surface cast iron disc, increased, which governed the interface stability. The novelty of this investigation lies in the identification of the parameters on which interface stability depends.