Wear Resistance of Organic Nanocomposites

2007 ◽  
Vol 334-335 ◽  
pp. 605-608 ◽  
Author(s):  
Hong Gang Zhu ◽  
Ricky S.C. Woo ◽  
Christopher K.Y. Leung ◽  
Jang Kyo Kim
Keyword(s):  
Wear Resistance ◽  
Coefficient Of Friction ◽  
Neat Epoxy ◽  
Testing Methods ◽  
Abrasion Test ◽  
Modified Clay ◽  
The Coefficient Of Friction ◽  
Short And Long Term ◽  
Ball On Disc

The wear resistance of epoxy-based nanocomposites reinforced with octadecylamine-modified clay was studied. Two testing methods, including the ball-on-disc abrasion test and the nanoscratch test, were used to measure the macro- and micro-wear behaviors. The ball-on-disc abrasion test suggests that the short- and long-term wear behaviors of neat epoxy and 5wt% nanoclay composites were similar, although the wear resistance as measured by the volume of material removed was greater for the clay nanocomposite than for the neat epoxy. The incorporation of nanoclay into the epoxy showed little effect on the coefficient of friction.

ANALYSIS OF FRACTURE AND WEAR RESISTANCE OF ZrN COATINGS

Tribologia ◽  
2018 ◽  
Vol 273 (3) ◽  
pp. 39-45 ◽  
Author(s):  
Kinga CHRONOWSKA-PRZYWARA ◽  
Marcin KOT
Keyword(s):  
Wear Resistance ◽  
Coefficient Of Friction ◽  
Coating Thickness ◽  
Elasticity Modulus ◽  
Scratch Test ◽  
The Coefficient Of Friction ◽  
Steel Substrates ◽  
Resistance Tests ◽  
Ball On Disc

The article presents the results of mechanical and tribological studies of ZrN coatings that allowed the determination of their hardness, elasticity modulus, and scratch and wear resistance. Tests were carried out for 1, 1.4, and 2 μm thick ZrN coatings deposited on X5CrNi18-10 austenitic steel substrates by PVD technology. Hardness and Young's modulus of coatings, evaluated by nanoindentation, were within the 26–32 GPa, and 330–360 GPa ranges, respectively. Analysis of the adhesion of the coating to the substrate was carried out based on the results of the scratch test. The highest critical load values of LC1 and LC2 were measured for the 1.4 μm thick coating. Tribological tests performed using a ball-on-disc tribotester showed that the wear resistance increases with coating thickness. This was accompanied by a reduction of the coefficient of friction from 0.22 to 0.17.

scholarly journals Friction Behavior of Pre-Damaged Wet-Running Multi-Plate Clutches in an Endurance Test

Lubricants ◽  
2020 ◽  
Vol 8 (7) ◽  
pp. 68
Author(s):  
Thomas Schneider ◽  
Katharina Voelkel ◽  
Hermann Pflaum ◽  
Karsten Stahl
Keyword(s):  
Coefficient Of Friction ◽  
Later Life ◽  
Second Step ◽  
Experimental Investigations ◽  
Endurance Test ◽  
Friction Behavior ◽  
Speed Range ◽  
The Coefficient Of Friction ◽  
Endurance Tests

Wet-running multi-plate clutches should be prevented from failing due to the often safety-relevant functions they fulfill in the drive train. In addition to long-term damage, spontaneous damage is of particular relevance for failures. This paper focuses on the influence of spontaneous damage on frictional behavior in the later life cycle. The aim of the experimental investigations is to initially cause spontaneous damage in wet-running multi-plate clutches with sintered friction linings. For this purpose, three clutches are first pre-damaged in stage tests with different intensities, so that the first spontaneous damage (local discoloration, sinter transfer) occurs. In the second step, an endurance test is carried out with the pre-damaged clutch packs and a non-pre-damaged reference clutch. The friction behavior of the clutches during the endurance test is compared and evaluated. It shows that local discoloration and sinter transfer are no longer visible after the endurance tests. At the beginning of the endurance test, the values of coefficient of friction are higher over the entire speed range of the heavily pre-damaged clutches than with the slightly pre-damaged clutch and the non-pre-damaged reference clutch. At the end of the endurance test, it can be observed that the greater the pre-damage to the clutches is, the greater the coefficient of friction increases with decreasing sliding speed.

Development of Antifriction Materials Based on Polytetrafluoroethylene with Carbon Fibers and Tungsten Disulfide

2020 ◽  
Vol 992 ◽  
pp. 745-750
Author(s):  
A.P. Vasilev ◽  
T.S. Struchkova ◽  
A.G. Alekseev
Keyword(s):  
Wear Resistance ◽  
Polymer Composites ◽  
Carbon Fibers ◽  
Coefficient Of Friction ◽  
Tribological Properties ◽  
Relative Elongation ◽  
Tungsten Disulfide ◽  
Degree Of Crystallinity ◽  
Mechanical And Tribological Properties ◽  
The Coefficient Of Friction

This paper presents the results from the investigation of effect the carbon fibers with tungsten disulfide on the mechanical and tribological properties of PTFE. Is carried out a comparison of mechanical and tribological properties of polymer composites PTFE-based with carbon fibers and PTFE with complex filler (carbon fibers with tungsten disulfide). It is shown that at a content of 8 wt.% CF+1 wt.% WS2 in PTFE, wear resistance increases significantly while maintaining the tensile strength, relative elongation at break and low coefficient of friction at the level of initial PTFE. The results of X-ray analysis and investigation of SEM supramolecular structure and friction surfaces of PTFE and polymer composites are presented. It is shown that the degree of crystallinity of polymer composites increases in comparison with the initial PTFE. The images of scanning electron microscope reveal that particles of tungsten disulfide concentrating on the friction surface is likely responsible to a reduction in the coefficient of friction and increase the wear resistance of PTFE-based polymer composites with complex fillers.

The Influence of Nano-Silica on the Wear Resistance of Ceramic – Polymer Composites Intended for Dental Fillings

2009 ◽  
Vol 151 ◽  
pp. 135-138
Author(s):  
Joanna Siejka-Kulczyk ◽  
Joanna Mystkowska ◽  
Małgorzata Lewandowska ◽  
Jan R. Dabrowski ◽  
Krzysztof Jan Kurzydlowski
Keyword(s):  
Wear Resistance ◽  
Polymer Composites ◽  
Coefficient Of Friction ◽  
Volume Fraction ◽  
Tooth Enamel ◽  
Nano Particles ◽  
Human Tooth ◽  
Nano Silica ◽  
The Coefficient Of Friction ◽  
Composite Samples

Ceramic – polymer composites based on acrylic (bis–GMA) and urethane – methacrylate (UM) resins with a 60 % total volume fraction of filler consisting of micro particles of glass and nano-particles of silica were fabricated. The nano-silica contents were: 0, 10, 20 vol. %. The composite samples were subjected to wear tests using an occlusion simulator tester which applies reciprocating movement and cyclic loading on the test material. This method of testing provides some similarity to the masticatory pattern occurring in the mouth during eating. The enamel of a human tooth was used as a counter-sample. The coefficient of friction was determined and the wear resistance of the composite samples containing the various nano-silica contents was established. In addition, the relative influence of the composite composition on the rate of wear of the human tooth enamel was estimated. The results of the study indicate that the addition of nano-silica significantly improves the wear resistance of the ceramic – polymer composites and reduces the wear of enamel. It was found that the addition of nano-silica has no influence on the coefficient of friction. It was also established that composites based on UM resin show better wear resistance than those based on a mixture of bis-GMA and TEGDMA resin.

THE INFLUENCE OF UNIAXIAL COMPRESSION ON THE FRICTION COEFFICIENT (POLYMER–STEEL PAIR), WEAR, AND HARDNESS IN SELECTED THERMOPLASTICS

Tribologia ◽  
2018 ◽  
Vol 279 (3) ◽  
pp. 77-82 ◽  
Author(s):  
Maciej KUJAWA
Keyword(s):  
High Pressure ◽  
Wear Resistance ◽  
Friction Coefficient ◽  
Uniaxial Compression ◽  
Elastic Deformation ◽  
Coefficient Of Friction ◽  
Internal Diameter ◽  
Tension And Compression ◽  
The Coefficient Of Friction ◽  
Harsh Conditions

Plastic plain bearings are deformed during assembly. According to one of the leading manufacturers of plastic sliding elements, the bushing’s internal diameter may be reduced by up to 2.5%. Moreover, plastic sliding elements are increasingly used in harsh conditions (e.g., under high pressure). However, there are no papers that describe the influence of deformation under compression on the tribological properties of plastics. Specimens made of PTFE, PA6, and PE-HD were deformed while conducting the current research, and this deformation was maintained during cooperation with steel. The results of microhardness, wear, and the coefficient of friction tests were compared to data gathered during tests of non-deformed specimens. During deformation under compression (e ≈ 6%), microhardness lowered by up to 30% (PTFE). A significant reduction of hardness (by up to 15%) was observed when strain was only 2%, and up to this value of strain, there is mainly elastic deformation in the polymer. Changes of the coefficient of friction values were insignificant. In terms of PTFE and PE-HD, during deformation under compression up to e ≈ 6% , the block scar volumes were 20% and 40% larger, respectively, than the non-deformed form of specimens. In terms of PA6, the change in block scar volume was insignificant. It may seem that tension and compression ought to cause totally different effects. However, the comparison of the current results and the results described in the previous paper exposes that these two different processes led to the same effects – reducing hardness and increasing wear. Deformation of plastic sliding components as an effect of assembly appears to be minor; however, it affects polymer microhardness and wear resistance.

scholarly journals Experimental and Analytical Investigations on Tribological Properties of PTFE/AP Composites

Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4295
Author(s):  
Hai Wang ◽  
Annan Sun ◽  
Xiaowen Qi ◽  
Yu Dong ◽  
Bingli Fan
Keyword(s):  
Wear Resistance ◽  
Wear Rate ◽  
Coefficient Of Friction ◽  
Tribological Properties ◽  
Chemical Structure ◽  
Element Composition ◽  
Support Material ◽  
Test Conditions ◽  
Transfer Films ◽  
The Coefficient Of Friction

The tribological properties of polytetrafluoroethylene (PTFE)/AP (poly(para-phenyleneterephthalamide) (PPTA) pulp) composites under different test conditions (load: 2N, 10N; frequency: 1 Hz, 4 Hz; amplitude: 2 mm, 8 mm) were holistically evaluated. PTFE/AP composites with different AP mass ratios of 3%, 6%, and 12% as a skeleton support material were prepared. The coefficient of friction (COF) and wear rate were determined on a ball-on-disk tribometer. Furthermore, the morphology, element composition, and chemical structure of the transfer membrane were analyzed accordingly. The relationships between load, frequency, amplitude, and tribological properties were further investigated. According to the wear mechanism, AP enables effective improvement in the stiffness and wear resistance, which is also conducive to the formation of transfer films.

scholarly journals Effect of Bulk Current Density on Tribological Properties of Fe-W, Co-W and Ni-W Coatings

2015 ◽  
Author(s):  
S.A. Silkin ◽  
A.V. Gotelyak ◽  
N. Tsyntsaru ◽  
A.I. Dikusar ◽  
R. Kreivaitis ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Coefficient Of Friction ◽  
Current Density ◽  
Dry Friction ◽  
Scratch Test ◽  
Tribological Behaviour ◽  
The Coefficient Of Friction ◽  
Current Densities ◽  
Scratch Tests ◽  
The Given

Evaluation of tribological behaviour of Fe-W, Ni-W and Co-W coatings produced by electrodeposition at various bulk current densities (BCD) was under investigation in the given study. BCD does not have essential effect on the microhardness and wear characteristics of Fe-W and Co-W coatings. But the scratch tests reveal the presence of such influence. These tests showed superior wear resistance for the coatings obtained at low BCD. It was found that BCD has influence on wear resistance of Ni-W coatings under dry friction conditions. The BCD also has an influence on the coefficient of friction of Fe-W and Ni-W coatings at dry friction conditions. However, such an effect is opposite to that, observed at the scratch test.

Flaky and fullerene-like WS2 nanoparticles as tribologic and toughening additives for epoxy

2016 ◽  
Vol 231 (1-2) ◽  
pp. 55-61
Author(s):  
Dietmar Haba ◽  
Andreas Hausberger ◽  
Andreas J Brunner
Keyword(s):  
Fracture Toughness ◽  
Wear Resistance ◽  
Beneficial Effect ◽  
Coefficient Of Friction ◽  
Friction And Wear ◽  
Epoxy System ◽  
Pin On Disc ◽  
The Coefficient Of Friction ◽  
Dispersion Technique ◽  
Epoxy Systems

Just like MoS2, WS2 is known for its outstanding tribologic properties. When used as additives, both were found to considerably improve the tribologic behavior of epoxy, i.e., its coefficient of friction and wear resistance. The best improvements were obtained with WS2 or MoS2 nanoparticles, in particular if they had a fullerene-like morphology. Likewise, fullerene-like WS2 nanoparticles were shown to considerably enhance the fracture toughness of epoxy. It was thus hypothesized that the improved wear resistance could be due to the toughening effect rather than due to reduced friction. Our investigations showed that both flaky and fullerene-like WS2 nanoparticles can improve the fracture toughness of certain epoxy systems, while they can embrittle others. The beneficial effect on the epoxy’s wear resistance could not be confirmed either: The coefficient of friction and wear measured in pin-on-disc tests correlated insignificantly with the type or amount of nanoparticles used or the dispersion technique applied. The fact that the fracture toughness did not correlate with the measured wear suggests that the investigated epoxy system wears by adhesion rather than by abrasion. It is thus possible that tribologic additives like WS2 are unsuited for counteracting this wear mechanism. In a nutshell, both the toughening and the wear-reducing effect of flaky and fullerene-like WS2 nanoparticles seem to depend strongly on the particular epoxy system investigated.

Effect of hygrothermal aging on mechanical and tribological behaviors of short glass-fiber-reinforced PA66

2018 ◽  
Vol 32 (12) ◽  
pp. 1585-1600 ◽  
Author(s):  
Riadh Autay ◽  
Ahmed Njeh ◽  
Fakhreddine Dammak
Keyword(s):  
Wear Resistance ◽  
Glass Fiber ◽  
Coefficient Of Friction ◽  
Ambient Conditions ◽  
Polyamide 66 ◽  
Hygrothermal Aging ◽  
Tribological Behaviors ◽  
Short Glass Fiber ◽  
The Coefficient Of Friction ◽  
Short Glass

Mechanical and tribological behaviors of polyamide 66 reinforced by various weight fractions of short glass fiber were investigated. All studied materials were subjected to accelerated hygrothermal aging tests. Three-point bending flexural tests were carried out to determine the mechanical behavior. Reciprocating tribotester was employed to determine friction and wear behaviors. Tribological tests were carried out, without lubrication and under ambient conditions. Ball on flat contact configuration was adopted for friction tests. Wear tests were carried out against an abrasive counterface. Results showed that flexural strength and elastic modulus increased when increasing glass fiber rate for all tested materials. In the contrary, the coefficient of friction and the wear resistance decreased. Results showed that the hygrothermal aging decreased the flexural features and increased the coefficient of friction. The effect of hygrothermal aging on the wear resistance depends on the reinforcement rate.

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