THE EFFECTS OF SURFACE ROUGHNESS ON FRICTION REDUCTION AS THE RESULT OF SURFACE TEXTURING BY ABRASIVE JET MACHINING

Tribologia ◽  
2016 ◽  
Vol 267 (3) ◽  
pp. 195-204
Author(s):  
Sławomir WOŚ ◽  
Waldemar KOSZELA ◽  
Paweł PAWLUS
Keyword(s):  
Surface Roughness ◽  
Friction Force ◽  
Surface Texturing ◽  
Frictional Resistance ◽  
Friction Reduction ◽  
Textured Surfaces ◽  
Sliding Surfaces ◽  
Abrasive Jet Machining ◽  
Oil Pockets

Various machining methods are currently used to obtain the best co-action of sliding surfaces. Application of two-process surfaces led to a decrease of frictional resistance. Textured surfaces after abrasive jest machining are practical examples of two-process topographies. The results of the application of textured discs with the same array of oil pockets of similar sizes, but with different roughness in areas free of dimples, are presented in this paper. It was determined that after this type of machining, the effect of the friction force decrease was caused by surface texturing.

scholarly journals Fast laser surface texturing of spherical samples to improve the frictional performance of elasto-hydrodynamic lubricated contacts

Friction ◽  
2021 ◽  
Author(s):  
G. Boidi ◽  
P. G. Grützmacher ◽  
A. Kadiric ◽  
F. J. Profito ◽  
I. F. Machado ◽  
...  
Keyword(s):  
Surface Texturing ◽  
Hydrodynamic Pressure ◽  
Friction Reduction ◽  
Laser Surface Texturing ◽  
Textured Surfaces ◽  
Engineering Applications ◽  
Lubricated Contacts ◽  
Fluid Uptake ◽  
Direct Laser ◽  
Frictional Performance

AbstractTextured surfaces offer the potential to promote friction and wear reduction by increasing the hydrodynamic pressure, fluid uptake, or acting as oil or debris reservoirs. However, texturing techniques often require additional manufacturing steps and costs, thus frequently being not economically feasible for real engineering applications. This experimental study aims at applying a fast laser texturing technique on curved surfaces for obtaining superior tribological performances. A femtosecond pulsed laser (Ti:Sapphire) and direct laser interference patterning (with a solid-state Nd:YAG laser) were used for manufacturing dimple and groove patterns on curved steel surfaces (ball samples). Tribological tests were carried out under elasto-hydrodynamic lubricated contact conditions varying slide-roll ratio using a ball-on-disk configuration. Furthermore, a specific interferometry technique for rough surfaces was used to measure the film thickness of smooth and textured surfaces. Smooth steel samples were used to obtain data for the reference surface. The results showed that dimples promoted friction reduction (up to 20%) compared to the reference smooth specimens, whereas grooves generally caused less beneficial or detrimental effects. In addition, dimples promoted the formation of full film lubrication conditions at lower speeds. This study demonstrates how fast texturing techniques could potentially be used for improving the tribological performance of bearings as well as other mechanical components utilised in several engineering applications.

Modeling of Surface Topography for Reduced Friction

2008 ◽  
Author(s):  
Marko Sedlacˇek ◽  
Bojan Podgornik ◽  
Jozˇe Vizˇintin
Keyword(s):  
Surface Roughness ◽  
Surface Topography ◽  
Surface Texturing ◽  
Test Results ◽  
Textured Surfaces ◽  
Roughness Parameters ◽  
Contact Conditions ◽  
Surface Roughness Parameters ◽  
Pin On Disc ◽  
Texture Size

The aim of the present research was to investigate surface topography in terms of different surface roughness parameters and to correlate surface topography change to friction of contact surfaces. For this purpose, different 100Cr6 plate samples with different surface topography were prepared. Using different grades and combinations of grinding and polishing samples with similar Ra values, but different Rku and Rsk values were obtained. To evaluate influence of roughness parameters on friction and wear, dry and lubricated pin-on-disc tests were carried out under different contact conditions. Test results indicate that high Rku and negative Rsk values lead to decrease in friction. To investigate the effect of surface texturing on surface roughness parameters, real roughness profiles were virtually altered to achieve virtually textured surfaces. Using NIST SMATS softgauge for calculation of surface roughness parameters, virtually altered roughness profiles were investigated in terms of texture size, shape and spacing, and their influence on surface roughness parameters, especially on skewness and kurtosis. Lower diameter, higher spacing and wedge-shaped dimples reflect in higher Rku and more negative Rsk parameters.

Sliding energy of textured surfaces via pendular tests

2019 ◽  
Vol 72 (9) ◽  
pp. 1051-1057
Author(s):  
Gabriel Ferri ◽  
Leonardo Dias ◽  
Ruan de Carvalho ◽  
Henara Costa
Keyword(s):  
Surface Texturing ◽  
Low Carbon Steel ◽  
Average Diameter ◽  
Evaluation Methodology ◽  
Low Carbon ◽  
Textured Surfaces ◽  
Content Type ◽  
Sliding Surfaces ◽  
Lubrication Conditions ◽  
Effect Of Surface

Purpose 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. Design/methodology/approach 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. Findings 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. Originality/value 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.

Laser Texturing of Sliding Surfaces of Bearings and Pump Seals

2014 ◽  
Vol 630 ◽  
pp. 301-307 ◽  
Author(s):  
Bogdan Antoszewski ◽  
Viacheslav Tarelnyk
Keyword(s):  
Silicon Carbide ◽  
Heat Flow ◽  
Surface Texturing ◽  
Operating Parameters ◽  
Textured Surfaces ◽  
Laser Technology ◽  
Sliding Surfaces ◽  
Micro Flow ◽  
Flow Stimulation ◽  
Selection Of

Surface texturing is more and more frequently used in modern machines to attain such aims as lubrication enhancement, heat flow intensification and micro-flow stimulation. The development of technologies using concentrated energy flux, e.g. laser technology, has contributed to it. Pumps contain a lot of elements where textured surfaces can be used. The article concentrates on the selection of operating parameters of a picoseconds laser used to produce texturing in elements made of steel, bronze and silicon carbide.

scholarly journals Laser Surface Texturing and Characterization of Austenitic Stainless Steel for the Improvement of Its Surface Properties

2021 ◽  
Author(s):  
Yassmin Seid Ahmed ◽  
Jose Mario Paiva ◽  
Fred L. Amorim ◽  
Ricardo D. Torres ◽  
Wagner de Rossi ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Surface Texturing ◽  
Laser Surface ◽  
Laser Surface Texturing ◽  
Textured Surfaces ◽  
Aisi 304 ◽  
Steel Aisi

Abstract A detailed investigation of laser textured surfaces produced on austenitic stainless steel (AISI 304) was carried out. Three different textures were produced by a Ti sapphire laser. The processed surfaces were characterized by surface morphology, phase structure, micro-hardness, surface roughness, and wettability. A ball-on-disk tribometer was used to study the tribological performance of both untextured and textured samples. The experimental observations demonstrate that laser surface texturing (LST) improves both surface wettability and surface roughness. Average surface roughness (Ra) was increased by 350% and the contact angle was reduced from 43° to 22°. The textured surfaces show a lower coefficient of friction and better wear resistance than the untextured surface. Out of the investigated patterns, the square textures exhibited a maximum reduction of 68% in the friction coefficient and a 50% lower wear rate.

scholarly journals Effect of Low Depth Surface Texturing on Friction Reduction in Lubricated Sliding Contact

Lubricants ◽  
2018 ◽  
Vol 6 (3) ◽  
pp. 62 ◽  
Author(s):  
Haytam Kasem ◽  
Ori Stav ◽  
Philipp Grützmacher ◽  
Carsten Gachot
Keyword(s):  
Research Work ◽  
Surface Texturing ◽  
Friction Reduction ◽  
Laser Surface Texturing ◽  
Surface Pattern ◽  
Textured Surfaces ◽  
Laser Interference ◽  
Wear Properties ◽  
Direct Laser ◽  
Direct Laser Interference Patterning

Laser surface texturing is an interesting possibility to tailor materials’ surfaces and thus to improve the friction and wear properties if proper texture feature sizes are selected. In this research work, stainless steel surfaces were laser textured by two different laser techniques, i.e., the direct laser interference patterning by using a nanosecond pulsed Nd:YAG laser and additionally by an ultrashort pulsed femtosecond Ti:Sa. The as-textured surfaces were then studied regarding their frictional response in a specially designed linear reciprocating test rig under lubricated conditions with a fully formulated 15W40 oil. Results show that dimples with smaller diameter lead to a significant reduction in the coefficient of friction compared to the dimples with a larger diameter and surfaces with a grid-like surface pattern produced by direct laser interference patterning.

scholarly journals Selected Methods and Applications of Anti-Friction and Anti-Wear Surface Texturing

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3227
Author(s):  
Slawomir Wos ◽  
Waldemar Koszela ◽  
Pawel Pawlus
Keyword(s):  
Energy Consumption ◽  
Wear Surface ◽  
Lower Energy ◽  
Friction And Wear ◽  
Surface Texturing ◽  
Friction Reduction ◽  
Energy Losses ◽  
Surface Textures ◽  
Abrasive Jet Machining ◽  
Wear Reduction

The constant development of environmental protection causes the necessity to increase the efficiency of machines. By increasing the efficiency of machines, energy losses can be limited, leading to lower energy consumption. Friction reduction leads to an increase in efficiency and a decrease in wear. In this paper, selected surface texturing methods, such as burnishing and abrasive jet machining, with their limitations are presented. Thanks to those processes, various surface textures can be obtained. Examples of applications of these methods for friction and wear reduction are shown.

THE EFFECT OF OIL POCKET ARRAYS ON FRICTION COEFFICIENT

Tribologia ◽  
2017 ◽  
pp. 97-105 ◽  
Author(s):  
Sławomir WOŚ ◽  
Waldemar KOSZELA ◽  
Paweł PAWLUS
Keyword(s):  
Surface Texturing ◽  
Area Ratio ◽  
Contact Conditions ◽  
Disc Surface ◽  
Abrasive Jet Machining ◽  
Random Arrangement ◽  
Before And After ◽  
Pin On Disc ◽  
Oil Pockets ◽  
Input Variables

Experiments were carried out using pin-on-disc tester in conformal lubricated contact conditions for different normal loads. Surface texturing was done using abrasive jet machining with the application of laser cut mask. In order to eliminate the effect of different input variables in all the experiments, pit-area ratio and sizes of oil pockets were very similar. Five types of oil pocket arrays were tested: radial, concentric, spiral, of a square arrangement, and of a random arrangement for 5% and 17% of pit-area ratio. Different dimple diameters caused various oil pocket densities. The experiments were also made for untextured polished discs. During tests, the friction force was monitored as a function of time. Before and after tests, disc surface topography was measured using a white light interferometer Talysurf CCI Lite. The beneficial effect of surface texturing was obtained for spiral arrays of dimples on disc surface. The presence of a radial array of oil pockets resulted in the worst tribological properties of tribological assemblies containing textured discs.

Effect of triangular oil pockets on friction reduction

2021 ◽  
pp. 135065012110446
Author(s):  
Slawomir Wos ◽  
Waldemar Koszela ◽  
Andrzej Dzierwa ◽  
Pawel Pawlus
Keyword(s):  
Coefficient Of Friction ◽  
Normal Load ◽  
Area Ratio ◽  
Apex Angle ◽  
Friction Reduction ◽  
Textured Surfaces ◽  
Disc Surface ◽  
Pin On Disc ◽  
Oil Pockets ◽  
Spiral Array

The effect of the apex angle of triangular oil pockets created on a disc surface on friction was studied. Experiments were carried out using an Optimol SRV5 tribotester equipped with a pin-on-disc module under unidirectional lubricated sliding. Both the sample and counter sample was made of steel of 45 Hardness Rockwell C (HRC) hardness. Only 1 ml of oil was put to the inlet side of the contact area at the beginning of each test. All textured surfaces had the same pit-area ratio and an average depth of dimples. Oil pockets were positioned in the spiral array. It was found that the effect of the apex angle of triangular dimples on friction reduction was important. When the normal load was lower, the smallest coefficient of friction was achieved for the sliding pair with a disc apex angle of 60°. Under a larger normal load, a higher apex angle corresponded to a higher coefficient of friction.

THE EFFECT OF SURFACE TEXTURING ON THE FRICTIONAL RESISTANCE OF STEEL-BRONZE ASSEMBLY IN LUBRICATED SLIDING

Tribologia ◽  
2018 ◽  
Vol 279 (3) ◽  
pp. 69-76
Author(s):  
Waldemar KOSZELA ◽  
Lidia GAŁDA ◽  
Andrzej DZIERWA ◽  
Paweł PAWLUS ◽  
Jarosław SĘP ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
Normal Load ◽  
Surface Texturing ◽  
Frictional Resistance ◽  
Mineral Oil ◽  
Area Density ◽  
42Crmo4 Steel ◽  
Constant Normal Load ◽  
Oil Pockets ◽  
Effect Of Surface

The experiments were carried out using a block-on-ring tester. The block samples made from bronze CuSn10P of 138 HB hardness were burnished to obtain surfaces with circular oil pockets. Rings were made from 42CrMo4 steel of hardness 40 HRC. Friction tests were conducted at a constant normal load of 900 N. Tests were carried out at increasing sliding speeds of the range 0.08 – 0.82 m/s, starting from the lowest speed. The every speed was maintained for two minutes. The tested assembly was inserted in the reservoir of mineral oil L-AN 46. It was found that the dimple presence on block surface reduced the friction coefficient substantially compared to non-textured turned surfaces. The area density of dimples smaller than 15% (particularly 4.5% and 6%) was beneficial.

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