scholarly journals A Study of Micro-Dimpled Groove Texture in Friction Reduction

2021 ◽  
Author(s):  
Yuan Wei ◽  
Xu Liu ◽  
Simon S. Park ◽  
Robert Tomkowski ◽  
Andreas Archenti
Keyword(s):  
Surface Texturing ◽  
Sample Surface ◽  
Green Technology ◽  
Friction Reduction ◽  
Laser Marking ◽  
Friction Control ◽  
The Coefficient Of Friction ◽  
Dimple Surface ◽  
Development Goals ◽  
Groove Texture

Abstract Friction control is a vital green technology for reaching sustainable development goals, and surface texturing is effective and efficient at reducing friction. In this study, a novel preparation scheme involving dimpled groove texture is proposed. A pulsed laser marking system is used to make the dimpled grooves. Due to the unique design and process to make the proposed texture, texturing time can be greatly minimized compared to the conventional micro-groove texture technology. A computational fluid dynamics (CFD) model that considers the dimple surface angle is employed to aid the design of the texture and to predict the performance of the texture under certain conditions. Reciprocating sliding tests are preformed to evaluate the effects of the texture on friction reduction. Textures with different densities are used in the experiments. The results suggest that the dimpled groove reduces the coefficient of friction by 6% with less density distribution on the sample surface; nevertheless, denser densities may reverse the result. The simulation results suggest that the texture may perform better under pressure of the lubricant film in hydrodynamic conditions.

scholarly journals An Experimental Study of Micro-Dimpled Texture in Friction Control under Dry and Lubricated Conditions

Micromachines ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 70
Author(s):  
Yuan Wei ◽  
Jesus Resendiz ◽  
Robert Tomkowski ◽  
Xu Liu
Keyword(s):  
Sustainable Development Goals ◽  
Surface Texturing ◽  
Friction Reduction ◽  
Experimental Conditions ◽  
Dominant Mechanism ◽  
Friction Control ◽  
The Coefficient Of Friction ◽  
Development Goals ◽  
Lubrication Conditions ◽  
Density Results

Friction control is a vital technology for reaching sustainable development goals, and surface texturing is one of the most effective and efficient techniques for friction reduction. This study investigated the performance of a micro-dimpled texture under varying texture densities and experimental conditions. Reciprocating sliding tests were performed to evaluate the effects of the micro-dimpled texture on friction reduction under different normal loads and lubrication conditions. The results suggested that a micro-dimpled texture could reduce the coefficient of friction (CoF) under dry and lubricated conditions, and high dimple density results in a lower CoF. The dominant mechanism of the micro-dimpled texture’s effect on friction reduction was discussed, and surface observation and simulation suggested that a micro-dimpled texture could reduce the contact area at the friction interface, thereby reducing CoF.

scholarly journals Possibilities of Dry and Lubricated Friction Modification Enabled by Different Ultrashort Laser-Based Surface Structuring Methods

Lubricants ◽  
2019 ◽  
Vol 7 (5) ◽  
pp. 43 ◽  
Author(s):  
Stefan Rung ◽  
Kevin Bokan ◽  
Frederick Kleinwort ◽  
Simon Schwarz ◽  
Peter Simon ◽  
...  
Keyword(s):  
Laser Beam ◽  
Surface Engineering ◽  
Surface Texturing ◽  
Friction Reduction ◽  
Surface Structures ◽  
Laser Surface Texturing ◽  
Periodic Surface ◽  
The Coefficient Of Friction ◽  
Disc Configuration ◽  
Micro Structures

In this contribution we report on the possibilities of dry and lubricated friction modification introduced by different laser surface texturing methods. We compare the potential of Laser-Induced Periodic Surface Structures and Laser Beam Interference Ablation on 100Cr6 steel in a linear reciprocating ball-on-disc configuration using 100Cr6 steel and tungsten carbide balls with load forces between 50 mN and 1000 mN. For dry friction, we find a possibility to reduce the coefficient of friction and we observe a pronounced direction dependency for surfaces fabricated by Laser Beam Interference Ablation. Furthermore, Laser-Induced Periodic Surface Structures result in a load-dependent friction reduction for lubricated linear reciprocating movements. This work helps to identify the modification behaviour of laser generated micro structures with feature sizes of approximately 1 µm and reveals new possibilities for surface engineering.

Investigation of a Unique Macro/Micro Laser Machined Feature for Mechanical Face Seals With Low Leakage, Low Friction, and Low Wear

2011 ◽  
Author(s):  
Lionel Young ◽  
Joshua Benedict ◽  
John Davis
Keyword(s):  
Density Ratio ◽  
Surface Texturing ◽  
Friction Reduction ◽  
Mechanical Seals ◽  
Low Friction ◽  
Face Area ◽  
Low Leakage ◽  
Dimple Surface ◽  
Micro Dimples ◽  
Tapered Channel

Numerous studies have been conducted to evaluate the effects of micro dimple surface texturing on friction reduction in mechanical seals [1–7]. Optimum ratios for a dimple configuration, depth (h) to diameter (D) (Fig. 1), range from 0.02 to 0.5, and area density ratio, ratio of dimple area to seal face area, range from 20 to 55%. Within this range it has been shown that friction can be reduced by as much as 50%. These studies indicate that if the ratio of depth to dimple diameter is reduced below 0.02 a dramatic reduction in performance is seen. Also observed in one investigation [8] is the possibility that micro dimples can become filled with debris. This may degrade performance over time. This report will show that with the use of a unique macro/micro feature it is possible to achieve a reduction in friction of 65%, significantly lower face temperature, exhibit debris resistance, showing low to zero measureable leakage, and low to zero wear when compared to an untextured seal face. The term macro/micro feature is used to describe a feature that has a depth to size ratio, h/L (Fig.2), which is two orders of magnitude smaller than current dimple configurations, well below what may be considered useful from a performance standpoint. This new macro/micro feature, a tapered channel, demonstrates significant cavitation affects as well as hydrodynamic load support. These features are believed to be responsible for its low leakage as well as it low friction/wear characteristics.

scholarly journals On the Microstructural, Mechanical and Tribological Properties of Mo-Se-C Coatings and Their Potential for Friction Reduction against Rubber

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1336
Author(s):  
Jorge Caessa ◽  
Todor Vuchkov ◽  
Talha Bin Yaqub ◽  
Albano Cavaleiro
Keyword(s):  
Carbon Content ◽  
Friction And Wear ◽  
Current Mode ◽  
Friction Reduction ◽  
Transition Metal Dichalcogenide ◽  
Butadiene Rubber ◽  
Wear Rates ◽  
Mechanical And Tribological Properties ◽  
The Coefficient Of Friction ◽  
Pin On Disk

Friction and wear contribute to high energetic losses that reduce the efficiency of mechanical systems. However, carbon alloyed transition metal dichalcogenide (TMD-C) coatings possess low friction coefficients in diverse environments and can self-adapt to various sliding conditions. Hence, in this investigation, a semi-industrial magnetron sputtering device, operated in direct current mode (DC), is utilized to deposit several molybdenum-selenium-carbon (Mo-Se-C) coatings with a carbon content up to 60 atomic % (at. %). Then, the carbon content influence on the final properties of the films is analysed using several structural, mechanical and tribological characterization techniques. With an increasing carbon content in the Mo-Se-C films, lower Se/Mo ratio, porosity and roughness appeared, while the hardness and compactness increased. Pin-on-disk (POD) experiments performed in humid air disclosed that the Mo-Se-C vs. nitrile butadiene rubber (NBR) friction is higher than Mo-Se-C vs. steel friction, and the coefficient of friction (CoF) is higher at 25 °C than at 200 °C, for both steel and NBR countersurfaces. In terms of wear, the Mo-Se-C coatings with 51 at. % C showed the lowest specific wear rates of all carbon content films when sliding against steel. The study shows the potential of TMD-based coatings for friction and wear reduction sliding against rubber.

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.

scholarly journals Biosorption of Pb(II) Using Coffee Pulp as a Sustainable Alternative for Wastewater Treatment

2021 ◽  
Vol 11 (13) ◽  
pp. 6066
Author(s):  
Dora Luz Gómez-Aguilar ◽  
Juan Pablo Rodríguez-Miranda ◽  
Deisy Baracaldo-Guzmán ◽  
Octavio José Salcedo-Parra ◽  
Javier Andrés Esteban-Muñoz
Keyword(s):  
Wastewater Treatment ◽  
Agricultural Waste ◽  
Green Technology ◽  
Point Of Zero Charge ◽  
Cellulose Content ◽  
The Sustainable Development ◽  
Coffee Pulp ◽  
Biosorption Process ◽  
Optimum Ph ◽  
Development Goals

The present research shows the results obtained from the biosorption process of Pb, using coffee pulp as a biosorbent in synthetic waters. To do this, the lignin and cellulose content and the percentage of removal of Pb2+ ions was determined; additionally, the sorption’s optimal variables, such as the optimum pH, the point of zero charge (pHpzc), the kinetics and the adsorption isotherm, were determined. A comparison was made with other by-products derived from coffee crops. According to the results obtained in this research, the cellulose percentage was 29.12 ± 0.22% and the lignin percentage was 19.25 ± 0.16% in the coffee pulp, the optimum pH was 2.0 units and the kinetic model, which adjusted to the biosorption’s process, was the pseudo-second order of Ho and McKay, presenting an isotherm of Langmuir’s model and pHpzc of 3.95 units. Lastly, the removal of the pollutant was 86.45%, with a capacity of maximum adsorption of 24.10 mg·g−1 obtained with a particle size of 180 µm, time of contact of 105 min and at 100 RPM. Finally, we express that (a) the coffee pulp can be used as a sustainable alternative for the removal of the pollutant mentioned in synthetic and/or industrial wastewater matrices, to meet goals 3.9 and 6.9 of the Sustainable Development Goals of the 2030 agenda, and (b) the novelty of this research is the use of an agricultural waste of easy acquisition as a sorbent, without chemical modification, since it presented a high percentage of efficiency in the removal of Pb2+ ions. In turn, the challenge of this research is implementing this green technology on a pilot, semi-industrial and/or industrial scale in wastewater treatment systems.

Tribological effects of laser surface texturing and residual stress

2018 ◽  
Vol 70 (1) ◽  
pp. 126-132 ◽  
Author(s):  
Shuwen Wang ◽  
Feiyan Yan ◽  
Ao Chen
Keyword(s):  
Residual Stress ◽  
Wear Resistance ◽  
Friction And Wear ◽  
Surface Texturing ◽  
Laser Surface ◽  
Friction Reduction ◽  
Laser Surface Texturing ◽  
Wear Testing ◽  
Content Type ◽  
Surface Textures

Purpose The purpose of this paper is to investigate the tribological effects of laser surface texturing (LST) and residual stress on functional surfaces. Design/methodology/approach 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. Findings 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. Originality/value 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.

STRATEGIES, CHALLENGES AND SOLUTIONS TOWARDS THE IMPLEMENTATION OF GREEN CAMPUS IN UiTM PERAK

2021 ◽  
Vol 19 (16) ◽  
Author(s):  
Haryati Mohd Isa ◽  
Daljeet Singh Sedhu ◽  
Nor Suzila Lop ◽  
Kushairi Rashid ◽  
Othman Mohd Nor ◽  
...  
Keyword(s):  
Sustainable Development ◽  
Environmental Sustainability ◽  
Technology Policy ◽  
Structured Interview ◽  
Green Technology ◽  
Sustainable Environment ◽  
Development Goals ◽  
Green Campus ◽  
Financial Awareness ◽  
Method Approach

Green initiatives have become a phenomenon globally now. This has taken seriously all parties regarding the process of environmental sustainability. Sustainable Development Goals had been used as a guideline towards this agenda. The Malaysian government issued the Green Technology Policy in July 2009 to accelerate the national economy and promote sustainable development. Meanwhile, green technology has been applied to universities in Malaysia to achieve green campus status under the UI Green Metric. Numerous universities in Malaysia have begun to take this issue seriously, including UiTM Perak. Three research objectives had been developed; (1) to determine strategies in promoting green campus in UiTM Perak, (2) to identify challenges in implementing green campus in UiTM Perak and (3) to recommend solutions to overcome the challenges in implementing green campus in UiTM Perak. A qualitative method approach by using a semi-structured interview with the Green Campus Committee had been adopted. The data is analysed using content analysis. The research revealed that despite several green initiatives implemented by UiTM Perak, there are also challenges occurring. Among them are financial, awareness and knowledge. To overcome these challenges, the management of UiTM Perak had outlined several actions to be taken. In conclusion, the green campus initiative can give many benefits towards a sustainable environment in UiTM Perak. Indeed, this agenda needs support by all parties.

scholarly journals Rubber plunger surface texturing for friction reduction in medical syringes

Friction ◽  
2018 ◽  
Vol 7 (4) ◽  
pp. 351-358 ◽  
Author(s):  
Haytam Kasem ◽  
Harel Shriki ◽  
Lihi Ganon ◽  
Michael Mizrahi ◽  
Kareem Abd-Rbo ◽  
...  
Keyword(s):  
Surface Texturing ◽  
Friction Reduction

Friction reduction in EHL contacts by surface microtexturing – tribological performance, manufacturing and tailored design

2019 ◽  
Vol 71 (8) ◽  
pp. 986-990 ◽  
Author(s):  
Stephan Tremmel ◽  
Max Marian ◽  
Michael Zahner ◽  
Sandro Wartzack ◽  
Marion Merklein
Keyword(s):  
Product Life Cycle ◽  
Structural Parameters ◽  
Surface Texturing ◽  
Friction Reduction ◽  
Forming Process ◽  
Friction Behavior ◽  
Holistic View ◽  
Content Type ◽  
Efficient Manufacturing ◽  
Tailored Design

Purpose This paper aims to derive tailor-made microtextures for elastohydrodynamically lubricated (EHL) contacts under consideration of manufacturing possibilities. Design/methodology/approach Component tests were used for the evaluation of the influence of surface texturing on the friction behavior in the cam/tappet contact. Furthermore, the manufacturing possibilities and limitations of a combined μEDM and micro-coining process and the feasibility of integration into a forming process were studied. Finally, a methodology based on transient EHL simulations and a meta-model of optimal prognosis was exemplarily used for microtexture optimization. Findings It was found that surface texturing in EHL contacts with high amount of sliding is promising. Moreover, the combination of μEDM and micro coining and the integration into established production processes allow the manufacturing of microtextures with desirable structural parameters and sufficient accuracy. Originality/value This paper gives a holistic view on surface microtexturing over several phases of the product life cycle, from the design, over efficient manufacturing to application-related testing.

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