Influence of the running-in process on the working ability of contact surfaces in lubricated sliding conditions

2021 ◽  
pp. 135065012110277
Author(s):  
Aleksandar Dimić ◽  
Aleksandar Vencl ◽  
Mileta Ristivojević ◽  
Radivoje Mitrović ◽  
Žarko Mišković ◽  
...  
Keyword(s):  
Wear Rate ◽  
Coefficient Of Friction ◽  
Experimental Testing ◽  
Normal Load ◽  
Operating Conditions ◽  
Operating Parameters ◽  
Working Ability ◽  
Contact Surfaces ◽  
Mixed Lubrication Regime ◽  
Lubricated Sliding

The influence of the running-in process operating parameters on tribological properties of the block-on-disc samples in lubricated sliding conditions is analyzed and discussed in detail. Different running-in regimes are achieved by varying the normal load and sliding speed. After the running-in period, during which the operating parameters are varied, all samples are placed in a working regime under the same set of operating conditions. At the end of the running-in period, as well as at the end of the working period, an analysis of the changes in the surface roughness, microhardness, wear rate, and coefficient of friction is performed. Less desirable properties in terms of wear rate and steady-state coefficient of friction are noticed for the samples that were run-in with the operating conditions which were the same as the working regime operating conditions. In the defined test conditions, it is shown that the intensity of normal load applied during the running-in process has a dominant influence on the amount of wear and coefficient of friction value. It was also shown that the running-in process can significantly improve the roughness of the initially rough contact surfaces. The results of experimental testing indicate that the variation of the operating parameters during the running-in process can be used to improve the working ability of the sliding contact surfaces under the mixed lubrication regime.

Modelling the tribological response in dry sliding of boron modified as-cast Ti6Al4V on hardened steel

2021 ◽  
pp. 135065012110592
Author(s):  
Palash Roy Choudhury ◽  
Korimilli Eswar Prasad ◽  
John K. Schueller ◽  
Abhijit Bhattacharyya
Keyword(s):  
Wear Rate ◽  
Coefficient Of Friction ◽  
Boron Content ◽  
Normal Load ◽  
Operating Conditions ◽  
Dry Sliding ◽  
Contour Plots ◽  
The Coefficient Of Friction ◽  
En 31 ◽  
Full Factorial

Tribological characteristics of boron modified as-cast Ti6Al4V alloys are not very well known, but these alloys enjoy improved as-cast mechanical properties and favourable manufacturing economy. Experimental results are reported here for the effects of sliding speed and normal load on the wear rate and the coefficient of friction in dry sliding of these alloys on hardened EN 31 steel. Alloys having 0%, 0.30%, and 0.55% boron by weight were tested. A full factorial experiment assessed the effects of boron content, speed, and load on wear and friction. Interactions between speed and load were found to be statistically significant in influencing the wear rate and the coefficient of friction. Regression models are developed to predict the wear rate and coefficient of friction responses. The developed contour plots can assist designers in choosing operating conditions when selecting these alloys even if the wear mechanisms are unknown. Evidence shows that the wear resistance of Ti6Al4V can be improved by boron addition, and wear regimes are sensitive to boron content.

Study on the effects of nano-aluminum-oxide particulates on mechanical and tribological characteristics of chopped carbon fiber reinforced epoxy composites

2015 ◽  
Vol 231 (4) ◽  
pp. 403-422 ◽  
Author(s):  
Kali Dass ◽  
SR Chauhan ◽  
Bharti Gaur
Keyword(s):  
Carbon Fiber ◽  
Wear Rate ◽  
Coefficient Of Friction ◽  
Normal Load ◽  
Epoxy Composites ◽  
Specific Wear Rate ◽  
Tribological Characteristics ◽  
X Ray ◽  
The Coefficient Of Friction ◽  
Mechanical And Tribological Characteristics

An experimental study has been carried out to investigate the mechanical and tribological characteristics of chopped carbon fiber (CCF) reinforced epoxy composites filled with nano-Al2O3 particulates, as a function of fiber and filler contents. The experiments were conducted using a pin-on-disc wear test apparatus under dry sliding conditions. The coefficient of friction and specific wear rate of these composites was determined as a function of applied normal load, sliding velocity, sliding distance, and reinforcement content. The tensile, flexural, and compression strengths of ortho cresol novalac epoxy and chopped carbon fiber (OCNE/CCF) filled composites are found to be within the ranges of 48–58.54 MPa, 115–156.56 MPa, and 48–61.15 MPa. Whereas the tensile, flexural, and compression strengths of OCNE/CCF/Al2O3-filled composites are found to be within the ranges of 96–110 MPa, 176–204.66 MPa, and 72–85.65 MPa, respectively. It has been observed that the coefficient of friction decreases and specific wear rate increases with increase in the applied normal loads. Further increases in the fiber (6 wt%) and particle (3 wt%) contents in the epoxy matrix resulted in a decrease of both the mechanical and tribological properties, but remains above that of the CCF reinforced epoxy composites. The worn surfaces of composites were examined with scanning electron microscopy equipped with energy dispersion X-ray analyzer and X-ray diffraction analysis technique to investigate the wear mechanisms.

Physical, mechanical and dry sliding wear properties of non-woven viscose fabric epoxy-based polymer composites: An optimization study

2021 ◽  
pp. 135065012110689
Author(s):  
Debabrata Panda ◽  
Krunal M Gangawane
Keyword(s):  
Polymer Composites ◽  
Sliding Wear ◽  
Normal Load ◽  
Operating Conditions ◽  
Dry Sliding Wear ◽  
Operating Parameters ◽  
Dry Sliding ◽  
Sliding Velocity ◽  
Wear Properties ◽  
Area Density

Polymer-based composites have been widely used in the enhanced tribological technologies of various automobile, aerospace industry, sports, etc. The epoxy-based polymer composites reinforced with glass fiber have significantly improved the wear inhibitors and ultimate strength along with ultra-low density than other available materials. This current research aims to fabricate a variation of such non-woven viscose-based polymer composites for various weight fractions (100–400 GSM) with a constant fiber loading of 30 wt% and subsequently analyze its physical, mechanical, and tribological properties under various operating parameters. The density of the fabricated composite exhibits an increase of magnitude with an increase in weight fraction. The composites consist of 400 GSM fabric showing a higher tensile, impact, flexural strength, hardness, and inter lamina shear strength (ILSS). A pin-on-disc wear set-up held dry sliding wear tests of various nonwoven viscose fabric-based composites under various operating parameters like sliding velocity, sliding distance, area density, and normal load. A Taguchi-based L16 orthogonal array design was utilized to estimate the optimal behavior for maximum wear resistance for operating conditions. The result reveals that the normal load over the composite contributes the highest towards wear on a composite compared to area density, sliding velocity, and distance. The wear phenomena have been verified with SEM micrographs to characterize various wear phenomena like fiber rapture, ploughing, micro-cracks, and wear lines.

INVESTIGATION ON DRY SLIDING WEAR BEHAVIOR OF TITANIUM DIOXIDE-REINFORCED MAGNESIUM MATRIX COMPOSITE

2021 ◽  
pp. 2150106
Author(s):  
P. C. ELUMALAI ◽  
R. GANESH
Keyword(s):  
Titanium Dioxide ◽  
Wear Rate ◽  
Coefficient Of Friction ◽  
Wear Mechanisms ◽  
Sliding Wear ◽  
Normal Load ◽  
Dry Sliding Wear ◽  
Dry Sliding ◽  
Sliding Velocity ◽  
Significant Change

In this work, the dry sliding wear behaviors of pure monolithic magnesium and magnesium–titanium dioxide (Mg–TiO2) composites were studied using pin-on-disc tribometer against an oil-hardened nonshrinking die steel (OHNS) counter-disc with a normal load of 0.5–2[Formula: see text]kg and a sliding velocity of 1.5–2.5[Formula: see text][Formula: see text] with the sliding distance and wear track diameter of 1500[Formula: see text]m and 90[Formula: see text]mm, respectively. The pin samples were characterized for their microstructural, nanomechanical and tribological properties such as wear rate, coefficient of friction and wear fractographs. Scanning electron microscopy (SEM) was used to analyze the worn-out surfaces of each pin sample in order to identify the different types of wear and wear mechanisms and the chemical constituents of each element were quantified by energy-dispersive spectroscopy. The influence of TiO2 reinforcements on the nanomechanical behavior was studied by nanoindentation technique. As compared with pure Mg, the nanoindentation strengths of Mg–1.5TiO2, Mg–2.5TiO2 and Mg–5TiO2 composites were found to increase by 11.9%, 22.2% and 35.8%, respectively, which was due to the addition of TiO2 particles and also due to the good bonding at the interface of TiO2 and magnesium particles. From the wear test results, a significant change in wear rate was observed with the change in normal load than that of sliding speed, whereas a significant change in coefficient of friction was noticed with the changes in both normal load and sliding velocity. The dominant wear mechanisms involved under the testing conditions were identified through plotting the contour maps and SEM fractographs. Also, from the fractographs it was noticed that delamination and plowing effect have been the significant wear mechanisms observed during low wear rate of samples, whereas melting, delamination and oxidation wear have been observed during high wear rate of pure Mg and its composites.

Tribological Characterization of Hypereutectic Al–25Si Alloy Under Dry and Lubricated Sliding Conditions

2017 ◽  
Vol 140 (1) ◽  
Author(s):  
Parveen Kumar ◽  
M. F. Wani
Keyword(s):  
Wear Rate ◽  
Friction And Wear ◽  
Normal Load ◽  
Experimental Studies ◽  
Three Dimensional ◽  
Solidification Process ◽  
Wear Properties ◽  
Sliding Distance ◽  
Lubricated Sliding

Friction and wear properties of hypereutectic Al–25Si alloy were studied under dry and lubricated sliding conditions. Hypereutectic Al–25Si alloys were prepared by rapid solidification process (RSP) under the T6 condition. Experimental studies were conducted using a ball on disk type tribometer. The effect of the sliding distance and normal load on the friction and wear were investigated. The coefficient of friction (COF) remained stable with an increase in the sliding distance (250–1500 m) and decreased with an increase in the normal load (10–50 N), whereas the wear rate decreased with an increase in the sliding distance, and increased with the increase in the normal load up to 40 N and then attained a steady-state value under dry and lubricated sliding conditions. The improvements in COF and wear rate were mainly attributed to the morphology, size, and distribution of hypereutectic Si particles due to its fabrication process. Scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), optical microscopy, and three-dimensional (3D)-surface profilometer were used for characterization of the wear tracks. The dominant wear mechanisms for a hypereutectic Al–25Si alloy were adhesive wear, abrasive wear, and plastic deformation.

Cast In-Situ Al (Mg,Mo)-Al2O3 (MoO3) Composite: Characterization and Tribological Behavior

Tribology ◽  
2005 ◽  
Author(s):  
Abdulhaqq Q. Hamid ◽  
Sataish C. Jain ◽  
Prakriti K. Ghosh ◽  
Subrata Ray
Keyword(s):  
Wear Rate ◽  
Coefficient Of Friction ◽  
Molten Aluminum ◽  
Normal Load ◽  
Processing Temperature ◽  
In Situ Composite ◽  
Rate Of Increase ◽  
Alumina Particles ◽  
The Coefficient Of Friction

Aluminum alloy-based cast in-situ composite has been synthesized by dispersion of externally added molybdenum trioxide particles (MoO3) in molten aluminum at the processing temperature of 850 °C. During processing, displacement reaction between molten aluminum and MoO3 particles, results in formation of alumina particles in-situ also releases molybdenum into molten aluminum. A part of this molybdenum forms solid -solution with aluminum and the remaining part reacts with aluminum to form intermetallic phase Mo(Al1−xFex)12 of different morphologies. Magnesium (Mg) is added to the melt in order to help wetting of alumina particles generated in-situ, by molten aluminum and help to retain these particles inside the melt. The mechanical properties (ultimate tensile stress, yield stress, percentage elongation and hardness) of the cast in-situ composite are relatively higher than those observed either in cast commercial aluminum or in cast Al-Mo alloys. The wear and friction of the resulting cast in-situ Al(Mg, Mo)Al2O3(MoO3) composites have been investigated using a pin-on-disc wear testing machine, at different normal loads of 9.8, 14.7, 19.6, 24.5, 29.4, 34.3 and 39.2 N and a constant sliding speed of 1.05 m/s, under dry sliding conditions. The results indicate that the cumulative volume loss and wear rate of cast in-situ composites are significantly lower than those observed either in cast commercial aluminum or in cast Al-Mo alloy, under similar load and sliding conditions. Beyond about 30-35 N loads, there appears to be a higher rate of increase in the wear rate in the cast in-situ composite as well as in cast commercial aluminum and cast Al-Mo alloy. For a given normal load, the coefficient of friction of cast in-situ composite is significantly lower than those observed either in cast commercial aluminum or cast Al-Mo alloy. The coefficient of friction of cast in-situ composite increases gradually with increasing normal load while those observed in cast commercial aluminum or cast Al-Mo alloy remain more or less the same. Beyond a critical normal load of about 30-35 N, the coefficient of friction decreases with increasing normal load in all the three materials.

ESTIMATION OF THE SPEED OF RO TION OF THE SPEED OF ROTATION OF GEARS IN OIL TION OF GEARS IN OIL DEPENDING ON THE LOAD

2020 ◽  
Vol 2020 (4) ◽  
pp. 192-199
Author(s):  
N Mirzayev ◽  
◽  
B Qurbonov
Keyword(s):  
Wear Rate ◽  
Friction Force ◽  
Friction Surface ◽  
Normal Pressure ◽  
Operating Conditions ◽  
Tabular Form ◽  
Wear Rates ◽  
Small Cracks ◽  
Contact Surfaces

This article shows the wear and the amount of load that occurs in the gears under different loads and under different operating conditions of the contact surfaces, and is given by the formulas. The values of loads and wear rates on gears are given in tabular form based on curves. According to the results of the study, an increase in the load value affects the wear rate, as well as the load values q = 100; 200; 300; 400; at N/mm, a decrease in the wear rate was found. The load concentration and accumulation of dislocations in the material, their approach and appearance of cracks, as well as the deep propagation of small cracks on the metal that occur mainly on the friction surface under the influence of normal pressure and friction force are studied.

scholarly journals MODELLING OF A GLASS GATHERER ROBOT'S ARM WITH A FRICTIONAL DAMPER

2018 ◽  
Vol 18 (4) ◽  
pp. 127-140
Author(s):  
Marek STEMBALSKI ◽  
Pawel PRES ◽  
Waclaw SKOCZYNSKI ◽  
Paweł TUREK
Keyword(s):  
Numerical Model ◽  
Finite Elements ◽  
Coefficient Of Friction ◽  
Normal Pressure ◽  
Operating Parameters ◽  
Sliding Velocity ◽  
Friction Damper ◽  
Damping Decrement ◽  
The Coefficient Of Friction ◽  
Contact Surfaces

A numerical model of a friction damper used for damping vibration in glass gatherer robots was described. The damper with a lance was modelled using finite elements. Primary natural frequency of the system was determined. Numerical calculations were performed to determine the best operating parameters of the damper for excitations using a impulse of a force. Results of the damping decrement calculations for the friction damper model with a constant coefficient of friction and for the model, in which the coefficient of friction varied depending on the sliding velocity and the normal pressure occurring at the contact surfaces of the damper’s friction rings, were presented. Based on numerical simulations, the values of relative displacements between the damper’s friction rings were also determined.

scholarly journals Microstructural Characterization and Evaluation of Sliding Wear of Hastelloy C276 under Different Loading Conditions

2019 ◽  
Vol 8 (12) ◽  
pp. 2841-2845
Keyword(s):  
Wear Rate ◽  
Coefficient Of Friction ◽  
Frictional Force ◽  
Sliding Wear ◽  
Normal Load ◽  
Dry Sliding Wear ◽  
Material Surface ◽  
Dry Sliding ◽  
Loading Conditions ◽  
Sem Images

Hastelloy C276 is investigated for dry sliding wear against an EN 31 stainless steel (hardness 60 HRC) at 298 K. The tribological properties such as frictional force, coefficient of friction and the wear rate on the material surface at different sliding distance are examined under different loading conditions. In the dry wear test at 40 N load, the wear rate increased by 300% as compared to 10, 20, 30 N loading conditions. The experimental results indicated reduction in coefficient of friction values and thus an increase in the frictional force with the increase in normal load. SEM images of worn out surfaces confirm that the delamination and adhesion causes the material removal from the surface in dry sliding. Further, the analysis of the hardness characteristics of worn out surfaces shows surface hardening during sliding wear process under 40 N load

Effect of Micro-Size Cenosphere Content on Friction and Dry Sliding Wear Behavior of Vinylester Composites – A Taguchi Method

2012 ◽  
Vol 585 ◽  
pp. 569-573 ◽  
Author(s):  
S.R. Chauhan ◽  
Sunil Thakur
Keyword(s):  
Wear Rate ◽  
Coefficient Of Friction ◽  
Sliding Wear ◽  
Friction And Wear ◽  
Normal Load ◽  
Dry Sliding ◽  
Sliding Speed ◽  
Applied Normal Load ◽  
The Coefficient Of Friction ◽  
Sliding Distance

In this paper the friction and wear characteristics of vinylester and vinylester composites have been investigated under dry sliding conditions for different applied normal load, sliding speed and sliding distance. The experiments have been carried on a pin on disc arrangement at normal room temperature conditions. The influence of friction and wear parameters like normal load, speed, sliding distance and percentage of filler content on the friction and wear rate has been investigated. In this study, a plan of experiments based on the techniques of Taguchi was performed to acquire data in a controlled way. An orthogonal array L27 (313) and Analysis of variance (ANOVA) were applied to investigate the influence of process parameters on the coefficient of friction and sliding wear behaviour of these composites. The Taguchi design of experiment approach eliminates the need for repeated experiments and thus saves time, material and cost. The results showed that with increase in the applied normal load and sliding speed the coefficient of friction and specific wear rate decreases under dry sliding conditions. It is also found that a thin film formed on the counterface seems to be effective in improving the tribological characteristics. The results showed that the inclusion of cenosphere as filler materials in vinylester composites will increase the wear resistance of the composite significantly.

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