Tribological properties friction property

Tribology The frictional properties of a material become important for press-fit connections. 

Keywords— Atomic Force Microscopy (AFM), Tribological Property, Frictional Coefficient, Surface Roughness, Cobalt-Chromium Femoral Head. 

Relatively few works considered the tribological properties of plasma-deposited a-C(N) H films. First, considering the coefficient of friction, nitrogen incorporation was not found to strongly modify it. Prioli et al. [93] studied the friction coefficient of a-C(N) H films against a Si3N4 probe in an atomic force microscope, in ambient air. Nitrogen incorporation up to about 10 at.% into the... 

The last few years have seen an explosion in the number of atomic-level tribological simulations aimed not just at understanding fundamental aspects of friction, but also at determining the frictional properties of systems used in real-world applications. In this section, we will discuss selected studies in an effort to demonstrate how the principles discussed earlier in this chapter are used in practice. Unfortunately, it is not possible to consider all of the important, high-caliber research within the space of this chapter. Instead, we focus on a few key areas that encompass both fundamental and applied research in computational tribology. 

Table 4.41 displays some examples of tribological properties of neat and reinforced polyamides (the figure preceding the reinforcement or additive indicates its % loading). The coefficients of friction are in a good range, from 0.1 up to 0.3 for the static coefficients, and wear varies from near 1 (excellent) up to more than 100 (fair). 

The wear resistance and coefficient of friction are suitable for tribological applications. Tribological properties for a PV of 1.75MPa.m/s are, for example ... 

Good mechanical properties dynamic fatigue behaviour tribological properties low coefficient of friction good heat and cold behaviours resistance to numerous chemicals such as typical hydrocarbons, oils, greases, solvents and oil products. 

The most likely application of the chalcogenide nanotubes is as solid lubricants. Mo and W chalcogenides are widely used as solid lubricants. It has been observed that the hollow nanoparticles of WS2 show better tribological properties and act as a better lubricant compared to the bulk phase in every respect (friction, wear and life-time of the lubricant).142 Tribological properties of 2H-MoS2 and WS2 powder can be attributed to the weak van der Waals forces between the layers which allow easy shear of the films with respect to each other. The mechanism in the WS2 nanostructures is somewhat different and the better tribological properties may arise from the rolling friction allowed by the round shape of the nanostructures. 

Bergmann, E., Malat, G., Muller, C. and Simon-Vermot, A., Friction Properties of Sputtered Dichaicogenide Layers, Tribology Inti., 14, 329, (1981). 

Extensive study has been carried out on the tribological properties of DLC. Different types of tribo-testers such as ball-on-disk and pin-on-disk have been used at low sliding speed or reciprocating conditions to find the friction coefficient as well as the wear rate of the coating. 

Tribology. These papers included M. D. Perry and J. A. Harrison, Molecular Dynamics Studies of the Frictional Properties of Hydrocarbon Materials Langmuir 12 (1996) 4552-4556 E. Manias, G. Hadziiannou and G. ten Brinke, Inhomogeneities in Sheared Ultrathin Lubricating Fluids, ibid 4587-4593 U. Landman, W. D. Luedtke and J. Gao, Atomic-scale Issues in Tribology Interfacial Junctions and Nano-elastohydrodynamics, ibid 4514-4528. 

Potassium titanate whiskers were found to improve the tribological properties of NAO friction materials. These soft, synthetic refractory materials stabilize friction level, reduce pad wear, noise, fade, thermal conductivity, control porosity, and provide thermal reinforcement. Fibrous potassium titanates are being replaced by platelet and powder versions because of health concerns associated with respirable fibers. 

Minami et al. [26] evaluated the tribological properties of trifluorotris (pentafluoroethyl) phosphate[(C2Fj)3PF3 and FAP]-derived ILs under boundary conditions. The anion in this case was more hydrophobic than that of bis (trifluoromethylsulfonyl)imide [(CF3S02)2N, TFSI]. For ILs with the same cations, FAP salts have generally much lower friction and better antiwear properties than the TFSI salts. 

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