Effects of Texture Density on Tribological Performance of Laser Peen Textured Surface

2013 ◽  
Vol 404 ◽  
pp. 106-111
Author(s):  
Kang Mei Li ◽  
Zhen Qiang Yao ◽  
Yong Xiang Hu
Keyword(s):  
Friction Coefficient ◽  
Carrying Capacity ◽  
Failure Time ◽  
Normal Load ◽  
Effective Means ◽  
Textured Surface ◽  
Load Carrying Capacity ◽  
Textured Surfaces ◽  
Texture Density ◽  
Load Carrying

Surface texturing has been recognized as an effective means to improve the tribological performances of sliding surfaces. Different densities of micro dimples were fabricated on Oxygen-Free High Conductivity (OFHC) copper by laser peen texturing (LPT). The tribological characteristics of the samples were tested by surface-to-surface sliding contact experiments under constant sliding velocity and linearly increased normal load. The effects of texture density on the friction coefficient, failure time and load carrying capacity were investigated. It was found that in comparison with smooth surfaces, textured surfaces help to reduce the friction coefficient, prolong the failure time and improve the load carrying capacity. Results also suggested that there might exit an optimum texture density with which the surface exhibits better tribological behavior than those with higher and lower texture densities.

Effect of Cavitation on Tribological Performances for Textured Surfaces

2012 ◽  
Vol 472-475 ◽  
pp. 391-394 ◽  
Author(s):  
Fan Ming Meng ◽  
Ling Zhang
Keyword(s):  
Fourier Transform ◽  
Friction Coefficient ◽  
Fast Fourier Transform ◽  
Carrying Capacity ◽  
Reynolds Equation ◽  
Load Carrying Capacity ◽  
Textured Surfaces ◽  
Force Load ◽  
Cavitation Effect ◽  
Load Carrying

The influence of cavitation in a lubricant between textured surfaces on tribological performances of the surfaces was investigated based on an extended Reynolds equation and other associated equations. The tribological performances of the surfaces holding dimples with divergent-convergent shape were analyzed with the cavitation effect consideration at different dimple numbers. In doing so, the elastic deformation of the surface is evaluated using continuous convolution fast Fourier transform (CC-FFT). Some mechanisms are revealed about the cavitation effect on the friction coefficient, friction force, load-carrying capacity and cavitated area of the textured surfaces.

Numerical and experimental investigation on influence of compound dimple on tribological performances for rough parallel surfaces

2017 ◽  
Vol 69 (4) ◽  
pp. 433-446 ◽  
Author(s):  
Fanming Meng ◽  
Zhitao Cheng ◽  
Tiangang Zou
Keyword(s):  
Friction Coefficient ◽  
Carrying Capacity ◽  
Tribological Performance ◽  
Textured Surface ◽  
Load Carrying Capacity ◽  
Friction Test ◽  
Content Type ◽  
Load Carrying ◽  
Parallel Surfaces ◽  
Simple Dimple

Purpose This study aims to explore the superiority of the compound dimple (e.g. the rectangular-rectangular dimple) and compare its tribological performance for rough parallel surfaces with those of the traditional one-layer dimple (simple dimple). Design/methodology/approach A mixed-lubrication model for a rough textured surface is established and solved using the finite difference method for film pressure and contact pressure. To accelerate the evaluation of surface deformation, the efficient Continuous convolution fast Fourier transform algorithm is applied. The effects of the compound dimple on the tribological performance for the rough parallel surfaces is numerically investigated. And these effects are compared with those of the simple dimple. Furthermore, a reciprocating friction test is conducted to verify the superiority of the compound dimple. Findings The compound dimple exhibits better tribological performances in comparison with the traditional simple dimple, that is, a larger load-carrying capacity and a smaller friction coefficient. To achieve the best tribological performances for the rough parallel surfaces, the depth ratio of the lower pore to the total pore of the compound dimple and the dimple interval should be reasonably chosen. For the surface with compound dimples, there exists an optimal surface roughness to simultaneously maximize the load-carrying capacity and minimize the friction coefficient. The smaller friction coefficient of the surface with compound dimples is verified by the reciprocating friction test. Originality/value The compound dimple is proposed and the superiority of this novel surface texture is confirmed. This study is expected to provide a new texturing method to improve the tribological performances of the traditional simple dimple.

Study on Tribological Performances for Textured Bearing of ICE

2013 ◽  
Vol 690-693 ◽  
pp. 1999-2002
Author(s):  
Fan Ming Meng ◽  
Tao Yang ◽  
Tao Long
Keyword(s):  
Friction Coefficient ◽  
Internal Combustion Engine ◽  
Carrying Capacity ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Load Carrying Capacity ◽  
Oil Film ◽  
Load Carrying ◽  
Inner Surface ◽  
Coupling Algorithm

The influence of dimples on the inner surface of big end bearing in internal combustion engine (ICE) on tribological performances of the bearing was investigated based on Navier-Strokes equation and other associated equations. In doing so, the CFD modulus in the software ANSYS12 version is used to analyze the dimple effect on the tribological performances of the bearing using two-way fluid-solid coupling algorithm. Some mechanisms are revealed about the dimple effect on the load-carrying capacity and friction coefficient of oil film, and the deformation and stress for the textured big end bearing.

Performance analysis of rough surface hybrid thrust bearing with elliptical dimples

2020 ◽  
pp. 135065012093198
Author(s):  
Vivek Kumar ◽  
Satish C Sharma
Keyword(s):  
Surface Roughness ◽  
Carrying Capacity ◽  
Machining Process ◽  
Fluid Film ◽  
Textured Surface ◽  
Stiffness Coefficient ◽  
Load Carrying Capacity ◽  
Power Losses ◽  
Load Carrying ◽  
Film Stiffness

Surface roughness is inherent to all machining processes. Therefore, even a high precision machining process renders micro-roughness to some extent on the surface of conventional materials. The asperities height of many rough engineering surfaces follows Gaussian distribution. The surface roughness on the bearing surface may significantly affect the bearing performance. Surface texturing is emerging as a new technique to improve the tribological behavior of the mating surfaces. Usually dimensions/height of micro-roughness is of order of the depth of surface textures in fluid film bearings. Neglecting micro-roughness while numerically simulating a textured surface bearing may generate inaccurate bearing performance data. In presented work, finite element simulation of textured surface hybrid thrust bearings has been performed. Surface texture is provided over thrust pad in the form of regular arrays of elliptical dimples. A parametric optimization is carried out to determine optimum attributes of elliptical dimple (axis, depth, texture length and orientation) so that the load-carrying capacity and fluid film stiffness should be maximized and film frictional power losses should be minimized. Use of textured surface (with optimum elliptical dimple attributes) results into a significant enhancement in load-carrying capacity (91.3%), film stiffness coefficient (+98.8%) and reduction in frictional power losses (−48.3%). It is also observed that elliptical dimple and micro-roughness (transverse orientation) generate synergistic effects in further enhancing the load-carrying capacity (+101.4%) and film stiffness coefficient (+112%) of the bearing.

Applicability of Interrupted Micro Cutting Process “Tilling” as Surface Texturing

2017 ◽  
Vol 749 ◽  
pp. 241-245 ◽  
Author(s):  
Hatsuhiko Usami ◽  
Toshiki Sato ◽  
Yasuyuki Kanda ◽  
Satoru Nishio
Keyword(s):  
Friction Coefficient ◽  
Tribological Properties ◽  
Cast Alloy ◽  
Effective Means ◽  
Frictional Resistance ◽  
Cnc Machining ◽  
Cutting Process ◽  
Textured Surface ◽  
Textured Surfaces ◽  
Micro Cutting

Tribological properties of textured surfaces fabricated using a discontinuous microcutting process were investigated. Aluminum cast alloy (AC8A) discs were used for the specimens. The texturing process was carried out using a CNC machining center with a cutting edge with a novel geometry. The resulting surface morphology consisted of micro dimples with a diameter of 200-300 μm and a depth of 5-10 μm, with controlled area fractions of 10 and 40% and a top region finished with a milling cut. The tribological properties were evaluated using a ring-on-disc type testing apparatus under lubricated conditions, and showed that the friction coefficient of the textured surfaces was low and stable from the beginning of the experiment. A dependence of the friction coefficient on the area fraction was also found. Further reductions in the friction coefficient were achieved on a textured surface with a polished top region. It can be concluded that the proposed discontinuous micro cutting process is an effective means of fabricating a micro texture for the reduction and stabilization of frictional resistance.

Static characteristics of misaligned multiple axial groove water-lubricated bearing in the turbulent regime

2016 ◽  
Vol 231 (3) ◽  
pp. 385-398 ◽  
Author(s):  
Ravindra Mallya ◽  
Satish B Shenoy ◽  
Raghuvir Pai
Keyword(s):  
Reynolds Number ◽  
Friction Coefficient ◽  
Carrying Capacity ◽  
Journal Bearing ◽  
Load Capacity ◽  
Turbulent Regime ◽  
Load Carrying Capacity ◽  
Static Characteristics ◽  
Load Carrying ◽  
Turbulence Effects

The static characteristics of misaligned three-axial water-lubricated journal bearing in the turbulent regime are analyzed for groove angles 36° and 18°. Ng and Pan’s turbulence model is applied to study the turbulence effects in the journal bearing. The static parameters such as load-carrying capacity, friction coefficient, and side leakage are found for different degree of misalignment (DM). The change in flow regime of the lubricant from laminar to turbulent and the increase in misalignment, improved the load capacity of the bearing. For lightly loaded bearings, the friction coefficient of the bearing increased with the increase in Reynolds number.

Partially Textured Slider and Journal Bearing Analysis

2012 ◽  
Vol 58 (2) ◽  
Author(s):  
T. V. V. L. N. Rao ◽  
A. M. A. Rani ◽  
T. Nagarajan ◽  
F. M. Hashim
Keyword(s):  
Friction Coefficient ◽  
Coefficient Of Friction ◽  
Carrying Capacity ◽  
Journal Bearing ◽  
Load Capacity ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
Bearing Analysis

The present study examines the influence of partial texturing of bearing surfaces on improvement in load capacity and reduction in friction coefficient for slider and journal bearing. The geometry of partially textured slider and journal bearing considered in this work composed of a number of successive regions of groove and land configurations. The nondimensional pressure expressions for the partially textured slider and journal bearing are derived taking into consideration of texture geometry and extent of partial texture. Partial texturing has a potential to generate load carrying capacity and reduce coefficient of friction, even for nominally parallel bearing surfaces.

An Analytical Solution for the Normal Load Carrying Capacity of Lightly Loaded Cylinders in Combined Rolling, Sliding and Normal Motion

1981 ◽  
Vol 103 (3) ◽  
pp. 467-468 ◽  
Author(s):  
T. F. Conry
Keyword(s):  
Analytical Solution ◽  
Film Thickness ◽  
Exponential Function ◽  
Carrying Capacity ◽  
Normal Load ◽  
Load Capacity ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
Minimum Film Thickness

The analytical solution for the normal load carrying capacity of lightly loaded cylinders in combined rolling, sliding and normal motion is obtained. It is shown that the load capacity is inversely proportional to the dimensionless minimum film thickness. The results are presented graphically and approximated in the form of an exponential function.

Performance Analysis of Full-Film Textured Surfaces With Consideration of Roughness Effects

2011 ◽  
Vol 133 (2) ◽  
Author(s):  
Y. Qiu ◽  
M. M. Khonsari
Keyword(s):  
Carrying Capacity ◽  
Load Carrying Capacity ◽  
Performance Parameters ◽  
Textured Surfaces ◽  
Roughness Effects ◽  
Thrust Bearings ◽  
Load Carrying ◽  
Cavitation Pressure ◽  
Simulated Surface ◽  
The Relationship

A mass-conservative algorithm that implements the Jakobsson–Floberg–Olsson cavitation theory is used to predict the performances of seal-like structures and thrust bearings with a dimpled surface texture. The results of a series of simulations for load-carrying capacity, film thickness, dimple depth, dimple density, cavitation pressure, leakage, and friction force are presented, and the relationship between these performance parameters is studied. It is shown that, under the conditions simulated, surface roughness can improve the load-carrying capacity, but its effect is limited.

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