Friction and Lubrication in the Deformation Processing of Metals : 2nd Report, Surface Texture and Coefficient of Friction

Surface texture plays an important role as it predominantly controls the frictional behavior and transfer layer formation at the contacting surfaces. In the present investigation, basic studies were conducted using inclined pin-on-plate sliding tester to understand the role of surface texture of hard material on coefficient of friction and transfer layer formation when sliding against soft materials. HCP materials such as pure Mg and pure Zn were used as pins while 080 M40 steel was used as plate in the tests. Two surface parameters of steel plates — roughness and texture — were varied in the tests. Tests were conducted in ambient conditions under both dry and lubricated conditions. The morphologies of the worn surfaces of the pins and the formation of transfer layer on the counter surfaces were observed using a scanning electron microscope. It was observed for both the pin materials that the occurrence of stick-slip motion, the transfer layer formation and the value of coefficient of friction as well as its two components, namely, adhesion and plowing, depend primarily on surface texture. The effect of surface texture on coefficient of friction was attributed to the variation of plowing component of friction for different surfaces. Both the plowing component of friction and amplitude of stick-slip motion were highest for the surface texture that promotes plane strain conditions while these were lowest for the texture that favors plane stress conditions at the interface.

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A Review of Surface Texture of Tribological Interfaces

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.37-38.41 ◽

2010 ◽

Vol 37-38 ◽

pp. 41-45 ◽

Cited By ~ 3

Author(s):

Zhi Wei Wang ◽

Mei Wei Chen ◽

Jian Wei Wu ◽

Hai Hui Zheng ◽

Xiao Feng Zheng

Keyword(s):

Modeling And Simulation ◽

Surface Texture ◽

Review Paper ◽

Tribological Performance ◽

Current Status ◽

Comprehensive View ◽

Lubrication Performance ◽

Mechanical Components ◽

Friction And Lubrication

Surface texture of tribological interfaces has the potential to improve friction and lubrication performance of various mechanical components. This review paper emphasizes on the current status of the research of surface texture, including the features, the effects on tribological performance, the forming techniques, and the modeling and simulation of surface texture. It is intended to help readers to gain a more comprehensive view on surface texture of tribological interfaces.

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Partial Slip Texture Slider and Journal Bearing Lubricated With Newtonian Fluids: A Review

Journal of Tribology ◽

10.1115/1.4039226 ◽

2018 ◽

Vol 140 (4) ◽

Cited By ~ 11

Author(s):

A. Senatore ◽

T. V. V. L. N. Rao

Keyword(s):

Coefficient Of Friction ◽

Surface Texture ◽

Journal Bearing ◽

Slip Surface ◽

Load Capacity ◽

Journal Bearings ◽

Newtonian Fluids ◽

Performance Characteristics ◽

Partial Slip ◽

Texture Properties

Partial slip texture surfaces have proven to be effective to improve load capacity and reduce coefficient of friction in slider and journal bearings. By controlling the partial slip surface texture properties, bearing with desired performance can be designed. It is of consequent interest to study the lubrication of slider and journal bearing systems taking into consideration design of partial slip texture surfaces. This paper aims at covering several investigation works related to slider and journal bearing lubricated with Newtonian fluids focusing on partial slip texture influence on bearing performance characteristics.

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The Effect of Surface Texture on Lubricated Fretting

Materials ◽

10.3390/ma13214886 ◽

2020 ◽

Vol 13 (21) ◽

pp. 4886

Author(s):

Agnieszka Lenart ◽

Pawel Pawlus ◽

Andrzej Dzierwa ◽

Slawomir Wos ◽

Rafal Reizer

Keyword(s):

Coefficient Of Friction ◽

Surface Texture ◽

Friction And Wear ◽

Normal Load ◽

Disc Surface ◽

The Coefficient Of Friction ◽

42Crmo4 Steel ◽

Ball Diameter ◽

Steel Balls ◽

Effect Of Surface

Experiments were conducted using an Optimol SRV5 tester in lubricated friction conditions. Steel balls from 100Cr6 material of 60 HRC hardness were placed in contact with 42CrMo4 steel discs of 47 HRC hardness and diversified surface textures. Tests were carried out at a 25–40% relative humidity. The ball diameter was 10 mm, the amplitude of oscillations was set to 0.1 mm, and the frequency was set to 80 Hz. Tests were performed at smaller (45 N) and higher (100 N) normal loads and at smaller (30 °C) and higher (90 °C) temperatures. During each test, the normal load and temperature were kept constant. We found that the disc surface texture had significant effects on the friction and wear under lubricated conditions. When a lower normal load was applied, the coefficient of friction and wear volumes were smaller for bigger disc surface heights. However, for a larger normal load a higher roughness corresponded to a larger coefficient of friction.

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Resistance of PLA Material Prepared By Additive Technology

ECS Transactions ◽

10.1149/10501.0319ecst ◽

2021 ◽

Vol 105 (1) ◽

pp. 319-327

Author(s):

Zbynek Studeny ◽

David Dobrocky ◽

Lenka Dobšáková ◽

Jiri Prochazka

Keyword(s):

Cyclic Loading ◽

3D Printing ◽

Coefficient Of Friction ◽

Surface Texture ◽

Test Specimen ◽

Sample Surface ◽

Test Area ◽

Reciprocating Motion ◽

Additive Technology ◽

The Coefficient Of Friction

The article studies the surface properties of PLA material prepared by additive technology, i.e. 3D printing. Samples with a square test area were printed by FFF technology. After 3D printing, the surface texture of the samples was evaluated in terms of microgeometry.Tribological tests were performed on the samples. The surface of the samples was cyclically stressed with the same load, always on the same path. Cyclic loading of the surface was performed on a UMT Bruker tribometer. The tribological properties between the sample surface and the test specimen in the shape of a ball were studied during the reciprocating motion. In particular, the coefficient of friction was measured and evaluated. The ball material was PTFE and Polypropylene.The wear parameters of samples and balls were documented and evaluated. The results of the tests are the load dependencies on the wear of the PLA material and the test specimens.

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Insight into friction and lubrication performances of surface-textured cylinder liners and piston rings

International Journal of Engine Research ◽

10.1177/14680874211050286 ◽

2021 ◽

pp. 146808742110502

Author(s):

Kai Ma ◽

Zhiwei Guo ◽

Chengqing Yuan

Keyword(s):

Surface Morphology ◽

Contact Resistance ◽

Surface Texture ◽

Friction And Wear ◽

Lubrication Mechanism ◽

Piston Rings ◽

Oil Storage ◽

Cavitation Effect ◽

Different Temperatures ◽

Friction And Lubrication

The effects of surface-texture technology on the friction and lubrication mechanism of cylinder liner-piston rings (CLPR) were explored in this study. An inclined groove texture was machined on the CL of a S195 diesel engine and dimples designed on the gas ring. Friction and wear tests of nontextured (NT), CL textured (CLT), and PR textured (PRT) conditions were performed on a CLTR friction and wear tester under different temperatures. First, the characteristics of friction and lubrication at different temperatures were analyzed by examining friction and contact resistance. Then, the wear characteristics were analyzed by examining surface morphology parameters of the CL and the PR wear mass after testing. Finally, the friction and lubrication mechanisms of NT, CLT, and PRT were studied by analyses of real-time friction and contact resistance in one cycle. The results showed that, under the same temperature, CLT and PRT increased oil film thickness, improved the lubrication state, and reduced friction, with CLT better than PRT in these respects. With increased temperature, the wear degree of CL liners became larger. The existence of surface texture reduced CL wear, yielded CL surface morphology not excessively changed by temperature, and improved its supporting performance and oil storage capacity. The inlet suction effect, structural effect, micro-wedge action, balancing wedge action, squeezing effect, and cavitation effect should be taken into account together when exploring the mechanism of the influence of surface texture on friction pairs. This study provided a method for scholars to explore the friction and lubrication mechanism of different texture types and provided an experimental basis for improving the performance of CLPR friction pairs.

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Technological Parameters Forming the Surface Texture in Hyper Productive Surface Plastic Deformation Processing

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.746.114 ◽

2017 ◽

Vol 746 ◽

pp. 114-119 ◽

Cited By ~ 13

Author(s):

Sergey N. Grigoriev ◽

N.M. Bobrovskij ◽

I.N. Bobrovskij ◽

Cho-Pei Jiang

Keyword(s):

Surface Roughness ◽

Plastic Deformation ◽

Cast Iron ◽

Surface Texture ◽

Processing Time ◽

High Strength ◽

Surface Plastic Deformation ◽

Surface Plastic ◽

Deformation Processing ◽

Productive Surface

The hyper productive surface plastic deformation processing technology called as wide burnishing (WB) was developed in Russian Federation. The mechanics of new WB technology is different from the classic SPD technologies (rolling or burnishing). For example applied force during processing of burnishing is 150-300 N, of WB is 2500-5000 N due to condition of process implementation in mass production with limited processing time (3-4 turnovers of workpiece). WB also has a high degree of deformation due to a multiple deformation passes. To determine the optimal WB processing parameters single and double instrumental devices were implemented and tested. Specimens made of steel 40 and high-strength cast iron 75-50-03 were tested. Initial roughness of steel 40 specimen’s surface was Ra = 0.5 microns and high-strength cast iron was Ra = 0.85 microns. Results of surface texture parameters of processed parts such as surface roughness Ra of steel 40 and high-strength cast iron 75-50-03 under varying load values P and number of cycles (the number of workpieces revolutions during the period of burnishing) were acquired. It was established that the minimum Ra value of the processed surface correspond with values of P = 210 N/mm2 for steel 40 and P = 410 N/mm2 for high-strength cast iron 75-50-03 regardless of number of burnishing cycles. Plastic deformation mechanism (processing time and pressure on the surface) influences on the processed surface roughness formation. It is possible to assume that straining state forms at the optimal values of P in terms of achieving a minimum value of Ra in which the reached degree of hardening allows to minimize the height of the microscopic irregularities of the previous grinding processing. In this case there is no plastic flow of the metal surface layer.

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Advanced Friction Modeling in Sheet Metal Forming

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.473.715 ◽

2011 ◽

Vol 473 ◽

pp. 715-722 ◽

Cited By ~ 1

Author(s):

J. Hol ◽

M.V. Cid Alfaro ◽

T. Meinders ◽

J. Huétink

Keyword(s):

Finite Element ◽

Sheet Metal ◽

Coefficient Of Friction ◽

Surface Texture ◽

Sheet Metal Forming ◽

Metal Forming ◽

Large Scale ◽

Friction Model ◽

Micro Scale ◽

Forming Simulations

The Coulomb friction model is frequently used for sheet metal forming simulations. This model incorporates a constant coefficient of friction and does not take the influence of important parameters such as contact pressure or deformation of the sheet material into account. This article presents a more advanced friction model for large-scale forming simulations based on the surface changes on the micro-scale. When two surfaces are in contact, the surface texture of a material changes due to the combination of normal loading and stretching. Consequently, shear stresses between contacting surfaces, caused by the adhesion and ploughing effect between contacting asperities, will change when the surface texture changes. A friction model has been developed which accounts for these microscopic dependencies and its influence on the friction behavior on the macro-scale. The friction model has been validated by means of finite element simulations on the micro-scale and has been implemented in a finite element code to run large scale sheet metal forming simulations. Results showed a realistic distribution of the coefficient of friction depending on the local process conditions.

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