scholarly journals Correlation between Mechanical Properties with Specific Wear Rate and the Coefficient of Friction of Graphite/Epoxy Composites

Materials ◽  
2015 ◽  
Vol 8 (7) ◽  
pp. 4162-4175 ◽  
Author(s):  
Mahdi Alajmi ◽  
Abdullah Shalwan
Keyword(s):  
Mechanical Properties ◽  
Wear Rate ◽  
Coefficient Of Friction ◽  
Epoxy Composites ◽  
Specific Wear Rate ◽  
The Coefficient Of Friction

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.

Dry Slide Wear Behavior of Graphite and SiC, TiO2 Filled the Unidirectional Glass-Epoxy Composites

2017 ◽  
Vol 25 (3) ◽  
pp. 193-198 ◽  
Author(s):  
A. Madhanagopal ◽  
S. Gopalakannan
Keyword(s):  
Wear Rate ◽  
Coefficient Of Friction ◽  
Wear Behavior ◽  
Specific Wear Rate ◽  
Dry Sliding ◽  
Testing Time ◽  
Time Duration ◽  
Sem Images ◽  
Unidirectional Glass ◽  
The Coefficient Of Friction

This study determines the friction and the wear properties of the unidirectional glass epoxy composite with Gr, SiC TiO2 powder by using pin on disk apparatus. This tribological data is obtained in dry sliding condition for a constant sliding time of 30 minutes. Test specimens are prepared using hand lay-up process and by varying the different (2, 5, 7) percentage each of graphite and SiC, TiO2 particles addition for the combination of fiber and matrix. The tests are performed by varying the operating parameters of contact pressure (p) and velocity (v). The composites (2% 5%, and 7%) are worn by dry sliding at the steel counter face under ambient conditions. The coefficient of friction reaches maximum of 0.78 at 2 kg load, 2 m/s velocity with testing time duration of 24 min. whereas 5%, 7% sample shows the coefficient of friction 0.28, 0.25 respectively. The specific wear rate value drops to 0.79 (mm3/N-m×10−6) at 2 kg load at 2 m/s velocity for the 5% specimen. The maximum reduction in the specific wear rate at 3 kg load, 1m/s velocity is 32.7 percentages, 5.63 percentages for the 5,7 percentage specimen compared to 2% specimen for the graphite and SiC, TiO2 particle filled composite specimen respectively. The SEM images are also taken to support the results.

scholarly journals Tribological investigation on oil blended with Additive using Response surface methodology

2020 ◽  
Vol 170 ◽  
pp. 01025
Author(s):  
Tushar Gadekar ◽  
Dinesh Kamble
Keyword(s):  
Response Surface Methodology ◽  
Wear Rate ◽  
Response Surface ◽  
Coefficient Of Friction ◽  
Comparative Investigation ◽  
Friction Model ◽  
Specific Wear Rate ◽  
Unknown Parameters ◽  
Pin On Disc ◽  
The Coefficient Of Friction

Friction and wear in dynamic parts is the primary reason for energy loss in gearbox lubrication system and this can be optimized by utilizing modified lubricant. The tribological nature of gearbox system is critically affected by factors such as type of lubricant, loading & speed etc. In latest years, multiple advanced oil and modern tribological techniques & instruments have been utilized to investigate behaviour of oil like pin on disc, Fourball tester etc. This paper presents comparative investigation of oil blended with additive for two different conditions using prediction model & RSM. The design of experimentations has been conducted by using response surface methodology. The value of inputs parameters such as concentration, load & sliding velocity ranges from 0.5 to 5 %, 60 to 100 N and 0.65 to 1.5 m/s, respectively are utilized to evaluate the outcomes of coefficient of friction and specific wear rate. At the end results from Prediction equations are compared with experimental literature based outcomes to signify the effect of parameters like blend %, load & Sliding speed. The Coefficient of friction model showed 47.57 % more closer outcomes as compared to the Specific wear rate model for specific variation of unknown parameters for pin on disc setup in oil.

Tribological behavior of an ultrahigh molecular weight polyethylene in lubricated environments

e-Polymers ◽  
2011 ◽  
Vol 11 (1) ◽  
Author(s):  
O. K. Kahyaoglu ◽  
H Unal ◽  
A Mimaroglu ◽  
S.H. Yetgin
Keyword(s):  
Molecular Weight ◽  
Wear Rate ◽  
Coefficient Of Friction ◽  
Salt Solution ◽  
Ultrahigh Molecular Weight Polyethylene ◽  
Specific Wear Rate ◽  
Distilled Water ◽  
Aisi 304L ◽  
Ultrahigh Molecular Weight ◽  
The Coefficient Of Friction

AbstractThe wear and friction performance of GUR 1020 grade ultrahigh molecular weight polyethylene (UHMWPE) polymer was studied in distilled water, HASS (Hank’s balanced salt solution) and several protein lubrication environments. Wear tests were carried out using polymer pin -on AISI 304L stainless steel disc apparatus. Tests conditions were room temperature, 40N, 80N and 120N applied loads and 0.5 m/s sliding speed. For the range of load and speed value of this work, the coefficient of friction and wear rate for UHMWPE polymer decreases with the increase in applied load values. The coefficient of friction is highest and the specific wear rate values is lowest under HASS +HA solution lubricant. The average specific wear rate values for UHMWPE polymer under distilled water and HASS+HA (Hank’s balanced salt solution with Hyaluronic acid) lubrication conditions are in the order of 9x10-15 m2/N and 3x10-15 m2/N respectively. The wear mechanism includes abrasion and adhesive processes.

scholarly journals Tribological Aspects, Optimization and Analysis of Cu-B-CrC Composites Fabricated by Powder Metallurgy

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4217
Author(s):  
Üsame Ali Usca ◽  
Mahir Uzun ◽  
Mustafa Kuntoğlu ◽  
Serhat Şap ◽  
Khaled Giasin ◽  
...  
Keyword(s):  
Weight Loss ◽  
Wear Rate ◽  
Coefficient Of Friction ◽  
Applied Load ◽  
Practical Significance ◽  
Tribological Characteristics ◽  
M 10 ◽  
Wide Range ◽  
The Coefficient Of Friction ◽  
Four Levels

Tribological properties of engineering components are a key issue due to their effect on the operational performance factors such as wear, surface characteristics, service life and in situ behavior. Thus, for better component quality, process parameters have major importance, especially for metal matrix composites (MMCs), which are a special class of materials used in a wide range of engineering applications including but not limited to structural, automotive and aeronautics. This paper deals with the tribological behavior of Cu-B-CrC composites (Cu-main matrix, B-CrC-reinforcement by 0, 2.5, 5 and 7.5 wt.%). The tribological characteristics investigated in this study are the coefficient of friction, wear rate and weight loss. For this purpose, four levels of sliding distance (1000, 1500, 2000 and 2500 m) and four levels of applied load (10, 15, 20 and 25 N) were used. In addition, two levels of sliding velocity (1 and 1.5 m/s), two levels of sintering time (1 and 2 h) and two sintering temperatures (1000 and 1050 °C) were used. Taguchi’s L16 orthogonal array was used to statistically analyze the aforementioned input parameters and to determine their best levels which give the desired values for the analyzed tribological characteristics. The results were analyzed by statistical analysis, optimization and 3D surface plots. Accordingly, it was determined that the most effective factor for wear rate, weight loss and friction coefficients is the contribution rate. According to signal-to-noise ratios, optimum solutions can be sorted as: the highest levels of parameters except for applied load and reinforcement ratio (2500 m, 10 N, 1.5 m/s, 2 h, 1050 °C and 0 wt.%) for wear rate, certain levels of all parameters (1000 m, 10 N, 1.5 m/s, 2 h, 1050 °C and 2.5 wt.%) for weight loss and 1000 m, 15 N, 1 m/s, 1 h, 1000 °C and 0 wt.% for the coefficient of friction. The comprehensive analysis of findings has practical significance and provides valuable information for a composite material from the production phase to the actual working conditions.

scholarly journals МОДЕЛЮВАННЯ ПРОЦЕСУ ТЕРТЯ В ТЕКСТИЛЬНИХ МАТЕРІАЛАХ

2020 ◽  
Vol 144 (2) ◽  
pp. 45-53
Author(s):  
Н. П. Супрун ◽  
М. Л. Рябчиков ◽  
І. О. Іванов
Keyword(s):  
Mechanical Properties ◽  
Coefficient Of Friction ◽  
Textile Material ◽  
Structural Elements ◽  
Friction Process ◽  
Textile Materials ◽  
Factors Influencing ◽  
The Coefficient Of Friction ◽  
Properties Of Materials ◽  
Main Factors

Create a model for determining the coefficient of friction of textile materials to identify the main factors influencing the process of friction, taking into account the structural and mechanical properties of materials. Modeling of friction process in textile materials as a combination of adhesive and elastic phenomena. Roughness of solid bodies and the main parameters of roughness, such as the height of micro-irregularities, their pitch, sharpening, etc. described in many standards and scientific papers. However, the modeling of the friction process in such systems is very complicated due to the irregularity of distribution of microroughness. The analysis of literature data showed that the surface roughness of textile materials is an important and effective factor in predicting the tactile properties of products for various purposes. Estimation of surface roughness is usually carried out using subjective and objective methods, and the latter can be contact and non-contact. The paper develops a model for determining the coefficient of friction of textile materials to identify the main factors influencing the friction process, taking into account the structural and mechanical properties of materials. Friction force is presented as a combination of two main factors. The first is the elastic resistance to deformation, the second is the adhesive resistance to compression of the structural elements of the material. The main parameters influencing the coefficient of friction of textile fabrics - modulus of elasticity of structural elements, their geometrical parameters - surface density of textile material, linear density of structural elements are established. The obtained results allow to qualitatively predict the friction forces of a textile material with known parameters of its structural elements, as well as to normalize these parameters to create materials with specified friction indices. The obtained results make it possible to select the threads that form the textile material, according to the values of the modulus of elasticity, thickness, location density to ensure the minimum friction force.

Tribological Properties of Polyoxymethylene Composites Against Aluminum

2003 ◽  
Vol 125 (3) ◽  
pp. 661-669 ◽  
Author(s):  
Masaya Kurokawa ◽  
Yoshitaka Uchiyama ◽  
Tomoaki Iwai ◽  
Susumu Nagai
Keyword(s):  
Wear Rate ◽  
Coefficient Of Friction ◽  
Tribological Properties ◽  
High Surface ◽  
Surface Hardness ◽  
Disk Surface ◽  
Optical Microscope ◽  
Transfer Film ◽  
The Other ◽  
The Coefficient Of Friction

Tribological properties of several kinds of polyoxymethylene (POM) composites were evaluated for the purpose of developing a polymeric tribomaterial especially suited for mating with aluminum parts having low surface hardness. POM composites containing small amounts of silicon carbide (SiC), POM/SiC; those containing a small amount of calcium octacosanonoate besides SiC, POM/SiC/Ca-OCA; and the one blended with 24 wt % of polytetrafluoroethylene, POM/PTFE(24); were injection-molded into pin specimens and their tribological properties were tested by means of a pin-on-disk type wear apparatus using an aluminum (A5056) mating disk in comparison with a 303 stainless steel (SUS303) disk. Evaluation was focused on observation of the sliding surfaces of the pin specimens and the mating disks by a scanning electron microscope and an optical microscope together with the measurement of surface roughness. In the case of mating against a SUS303 disk having high surface hardness, all pin specimens did not roughen the disk surfaces even after long time of rubbing. Only POM/PTFE(24) composite obviously made a transfer film on the disk surface, while the other composites made an extremely thin one on it. POM/SiC(0.1)/Ca-OCA(1) composite, containing SiC 0.1 wt. % and Ca-OCA 1 wt. %, was found to show the lowest coefficient of friction and the lowest wear rate forming extremely thin transfer film on the mating disk. On the other hand, against an A5056 disk which has lower surface hardness than that of SUS303 disk, unfilled POM and POM composites except POM/SiC(0.1)/Ca-OCA(1) composite roughened the disk surfaces. However, the sliding surface of the A5056 disk rubbed with POM/SiC(0.1)/Ca-OCA(1) composite was significantly smoother and that of the pin specimen was also quite smooth in comparison with other pin specimens. Further, when each POM composite was rubbed against the A5056 disk, formation of transfer film was not obvious on the disk surfaces. For POM/SiC(0.1)/Ca-OCA(1) composite, the wear rate was the lowest of all POM composites, and the coefficient of friction was as low level as 60 percent of that of unfilled POM, but slightly higher than that of POM/PTFE(24) composite. For POM/SiC(0.1)/Ca-OCA(1) composite, the nucleating effect of SiC and Ca-OCA, which accelerated the crystallization of POM during its injection molding to form a matrix containing fine spherulites, must have resulted in increasing the toughness of the matrix and lowering the wear rate. Also, the lubricant effect of Ca-OCA should have lowered the coefficient of friction of the same matrix for rubbing against aluminum mating disk. POM/SiC(0.1)/Ca-OCA(1) composite was concluded as an excellent tribomaterial for mating with aluminum parts.

Morphological Characteristics and Physical & Mechanical Properties of seeds of small-seeded crops

2020 ◽  
pp. 27-35
Author(s):  
Elchyn Aliiev ◽  
◽  
Christina Lupko ◽  
Keyword(s):  
Mechanical Properties ◽  
Coefficient Of Friction ◽  
Morphological Characteristics ◽  
Physical And Mechanical Properties ◽  
Specific Weight ◽  
Test Material ◽  
Effective Diameter ◽  
Morphological Parameters ◽  
Separation Processes ◽  
The Coefficient Of Friction

To create a database and systematize the seeds of samples of small-seeded crops, it is necessary to determine the patterns of influence of morphological parameters on their physical and mechanical properties. The development of the latest technologies and technical devices for cleaning and separation is possible due to the understanding of the characteristic morphological parameters for each of the small-seeded crops. The aim of the research is to determine the physical and mechanical properties of the seed material of small-seeded crops (mustard, flax, ryegrass, rapeseed), necessary to increase the efficiency of their cleaning and separation processes. To achieve this goal, a plan of experimental research was developed, which provided for the determination of physical and mechanical parameters of seeds of small-seeded crops, namely: indicators that characterize the flowability of seeds (angle of natural bias); frictional properties of seeds (static coefficient of friction); porosity (density) and density; size and mass characteristics of seeds (length, width, thickness, effective diameter, weight of 1000 seeds). It is established that the physical and mechanical properties of seeds of small-seeded crops are greatly influenced by its humidity. With increasing humidity, the performance of the test material increases. This is due to the fact that with increasing humidity, the shape of the seed almost turns into a spherical, which, in turn, leads to an increase in the curvature of the surface and reduce the points of contact between the seeds. As a result, the angle of natural inclination increases. The coefficient of friction of seeds of small-seeded crops depends on the roughness of the friction surface and decreases with increasing humidity. This is due to the fact that with increasing humidity decreases the forces of molecular attraction of the seed coat to the surface of the material. Seed density increases with increasing humidity. From this we can conclude that the absorption of moisture by the investigated material increases the total weight of the seed, and as a result - increases its specific weight.

Paper 21: Variations in Friction and Wear between Unlubricated Steel Surfaces

1966 ◽  
Vol 181 (15) ◽  
pp. 16-24
Author(s):  
S. W. E. Earles ◽  
D. G. Powell
Keyword(s):  
Wear Rate ◽  
Mild Steel ◽  
Oxide Layer ◽  
Coefficient Of Friction ◽  
Surface Film ◽  
Frictional Heating ◽  
Subsequent Increase ◽  
Track Condition ◽  
The Coefficient Of Friction ◽  
Steel Disc

Experiments have been conducted in a normal atmosphere using a 0·25-in diameter mild-steel pin specimen sliding on a 10-in diameter mild-steel disc. The ranges of normal force and speed are 0·5–10·4 lbf and 20–190 ft/s respectively. Initially the coefficient of friction is comparatively large, and the wear is of the severe metallic form. However, frictional heating causes rapid oxidation of the surfaces and, if the sliding distance is sufficient, the eventual retention of an oxide layer causes a rapid decrease in the coefficient of friction and the wear rate decreases by 3–4 orders of magnitude. At speeds above about 75 ft/s and loads below about 5 lbf the formation, after several hours' sliding, of a continuous oxide layer on the track causes a further reduction in the pin wear rate. At higher loads and/or lower speeds this track condition is not attained. At speeds of 75 ft/s and above there exists a critical load (the magnitude of which depends on speed) above which periodic removals of the surface film(s) occur producing metallic wear and high friction. However, the subsequent increase in oxidation allows conditions of mild wear to be re-established generally within a few seconds. The steady-state coefficient of friction has been observed to be a function of load1/2 × speed, and periodic surface breakdowns found to occur when load1/2 × speed exceeds 170 lbf1/2 ft/s, the frequency decreasing with increasing load or speed.

scholarly journals Reduction of the Coefficient of Friction of Steel-Steel Tribological Contacts by Novel Graphene-Deep Eutectic Solvents (DESs) Lubricants

Lubricants ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 37 ◽  
Author(s):  
Ignacio Garcia ◽  
Silvia Guerra ◽  
Juan de Damborenea ◽  
Ana Conde
Keyword(s):  
Mechanical Properties ◽  
Ionic Liquids ◽  
Friction Coefficient ◽  
Wear Rate ◽  
Adhesive Wear ◽  
Choline Chloride ◽  
Deep Eutectic Solvents ◽  
The Other ◽  
Graphene Flakes ◽  
The Coefficient Of Friction

Deep eutectic ionic liquids (DES) possess similar properties to conventional ionic liquids (ILs). However, ILs cannot be considered as environmentally friendly compounds due to both its processing and synthesis, which could have significant polluting effects. On the contrary, deep eutectic solvents (DESs) can be biodegradable, non-toxic, and have a lower price than most ILs, making them potentially useful in a wide variety of advanced technological applications, such as tribology. On the other hand, graphene has recently been proposed as an extremely promising lubricant due to its combination of mechanical properties and chemical stability as well as its “green” character. In the present paper, graphene flakes (≈250 nm) have been used as an additive to DES composed of choline chloride (ChCl)-urea, ChCl-ethylene glycol, and ChCl-malic acid. According to the results, the addition of 1 wt% graphene reduces friction coefficient (COF) and, notably, prevents adhesive wear, reducing wear rate on steel-steel sliding contacts.

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