Elemental analysis of a friction and wear surface during sliding using Auger spectroscopy.
Explore the source record for details and available documents.
Buckley, D. H.↗
SEARCH · Engineering Papers
Results for “SLIDING FRICTION”
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Finite elements for contact problems in two-dimensional elastodynamics
A finite element approach for contact problems in two dimensional elastodynamics was proposed. Sticking, sliding, and frictional contact were taken into account. The method consisted of a modification of the shape functions, in the contact region, in order to involve the nodes of the contacting body. The formulation was symmetric (both bodies were contactors and targets), in order to avoid interpenetration. Compatibility over the interfaces was satisfied. The method was applied to the impact of a block on a rigid target. It is shown that the formulation can be applied to fluid structure interaction, and to problems involving material nonlinearity.
Zimmermann, T. K.↗
Contact stresses in gear teeth: A new method of analysis
A new, innovative procedure called point load superposition for determining the contact stresses in mating gear teeth. It is believed that this procedure will greatly extend both the range of applicability and the accuracy of gear contact stress analysis. Point load superposition is based upon fundamental solutions from the theory of elasticity. It is an iterative numerical procedure which has distinct advantages over the classical Hertz method, the finite element method, and over existing applications with the boundary element method. Specifically, friction and sliding effects, which are either excluded from or difficult to study with the classical methods, are routinely handled with the new procedure. Presented here are the basic theory and the algorithms. Several examples are given. Results are consistent with those of the classical theories. Applications to spur gears are discussed.
Somprakit, Paisan↗
Contact stresses in gear teeth - A new method of analysis
A new, innovative procedure called point load superposition for determining the contact stresses in mating gear teeth is presented. It is believed that this procedure will greatly extend both the range of applicability and the accuracy of gear contact stress analysis. Point load superposition is based upon fundamental solutions from the theory of elasticity. It is an iterative numerical procedure which has distinct advantages over the classical Hertz method, the finite element method, and over existing applications with the boundary element method. Specifically, friction and sliding effects, which are either excluded from or difficult to study with the classical methods, are routinely handled with the new procedure. Presented here are the basic theory and the algorithms. Several examples are given. Results are consistent with those of the classical theories. Applications to spur gears are discussed.
Somprakit, Paisan↗
Friction and Wear Modifiers Using Solvent Partitioning of Hydrophilic Surface-interactive Chemicals Contained in Boundary Layer-targeted Emulsions
A wear and/or friction reducing additive for a lubricating fluid in which the additive is a combination of a moderately hydrophilic single-phase compound and an anti-wear and/or anti-friction aqueous salt solution. The aqueous salt solution produces a coating on boundary layer surfaces. The lubricating fluid can be an emulsion-free hydrophobic oil, hydraulic fluid, antifreeze, or water. Preferably, the moderately hydrophilic single-phase compound is sulfonated castor oil and the aqueous salt solution additionally contains boric acid and zinc oxide. The emulsions produced by the aqueous salt solutions, the moderately hydrophilic single-phase compounds, or the combination thereof provide targeted boundary layer organizers that significantly enhance the anti-wear and/or anti-friction properties of the base lubricant by decreasing wear and/or friction of sliding and/or rolling surfaces at boundary layers.
Richmond, Robert Chafee↗
Friction and Wear Modifiers Using Solvent Partitioning of Hydrophilic Surface-Interactive Chemicals Contained in Boundary Layer-Targeted Emulsions
A wear and/or friction reducing additive for a lubricating fluid in which the additive is a combination of a moderately hydrophilic single-phase compound and an anti-wear and/or anti-friction aqueous salt solution. The aqueous salt solution produces a coating on boundary layer surfaces. The lubricating fluid can be an emulsion-free hydrophobic oil, hydraulic fluid, antifreeze, or water. Preferably, the moderately hydrophilic single-phase compound is sulfonated castor oil and the aqueous salt solution additionally contains boric acid and zinc oxide. The emulsions produced by the aqueous salt solutions, the moderately hydrophilic single-phase compounds, or the combination thereof provide targeted boundary layer organizers that significantly enhance the anti-wear and/or anti-friction properties of the base lubricant by decreasing wear and/or friction of sliding and/or rolling surfaces at boundary layers.
Richmond, Robert Chaffee↗
Friction and Wear Modifiers Using Solvent Partitioning of Hydrophilic Surface-Interactive Chemicals Contained in Boundary Layer-Targeted Emulsions
A wear and/or friction reducing additive for a lubricating fluid in which the additive is a combination of a moderately hydrophilic single-phase compound and an anti-wear and/or anti-friction aqueous salt solution. The aqueous salt solution produces a coating on boundary layer surfaces. The lubricating fluid can be an emulsion-free hydrophobic oil, hydraulic fluid, antifreeze, water, or a water-based lubricant. Preferably, the moderately hydrophilic single-phase compound is sulfonated castor oil and the aqueous salt solution additionally contains boric acid and zinc oxide. The emulsions produced by the aqueous salt solutions, the moderately hydrophilic single-phase compounds, or the combination thereof provide targeted boundary layer organizers that significantly enhance the anti-wear and/or anti-friction properties of the base lubricant by decreasing wear and/or friction of sliding and/or rolling surfaces at boundary layers.
Richmond, Robert Chaffee↗
Friction and wear of oxide-ceramic sliding against IN-718 nickel base alloy at 25 to 800 C in atmospheric air
The friction and wear of oxide-ceramics sliding against the nickel base alloy IN-718 at 25 to 800 C were measured. The oxide materials tested were mullite (3Al2O3.2SiO2); lithium aluminum silicate (LiAlSi(x)O(y)); polycrystalline monolithic alpha alumina (alpha-Al2O3); single crystal alpha-Al2O3 (sapphire); zirconia (ZrO2); and silicon carbide (SiC) whisker-reinforced Al2O3 composites. At 25 C the mullite and zirconia had the lowest friction and the polycrystalline monolithic alumina had the lowest wear. At 800 C the Al2O3-8 vol/percent SiC whisker composite had the lowest friction and the Al2O3-25 vol/percent SiC composite had the lowest wear. The friction of the Al2O3-SiC whisker composites increased with increased whisker content while the wear decreased. In general, the wear-resistance of the ceramics improve with their hardness.
Sliney, Harold E.↗
Tribological evaluation of PS300: A new chrome oxide based solid lubricant coating sliding against Al2O3 From 25 to 650 C
This paper presents the tribological characteristics of Al203 sliding against PS300; a chrome oxide based self lubricating coating. Al203 pins were slid against PS300 coated superalloy disks in air, under a 4.9 N load at velocities of 1 to 8 m/s. At a sliding velocity of 1 m/s, friction ranged from 0.6 at 25 C to 0.2 at 650 C. Wear factors for the Al203 pins were in the 10(exp -7) mm(exp 3)/N-m range and for the PS300 coating was in the 10(exp -5) mm(exp 3)/N-m range. The test results suggest that increased surface temperature resulting from either frictional heating, generated by increased sliding velocity, or ambient heating caused a reduction in friction and wear of the sliding couple. Based upon these results, the tested material combination is a promising candidate for high temperature wear applications.
DellaCorte, C.↗
Wear rate and friction coefficient in liquid nitrogen and hydrogen of steel sliding on polymer laminates /various fabrics and polymers/
Wear rate and friction coefficient of steel sliding on polymer laminates determined in liquid nitrogen and hydrogen
Johnson, R. L.↗
Sliding Seal Materials for Adiabatic Engines, Phase 2
An essential task in the development of the heavy-duty adiabatic diesel engine is identification and improvements of reliable, low-friction piston seal materials. In the present study, the sliding friction coefficients and wear rates of promising carbide, oxide, and nitride materials were measured under temperature, environmental, velocity, and loading conditions that are representative of the adiabatic engine environment. In addition, silicon nitride and partially stabilized zirconia disks were ion implanted with TiNi, Ni, Co, and Cr, and subsequently run against carbide pins, with the objective of producing reduced friction via solid lubrication at elevated temperature. In order to provide guidance needed to improve materials for this application, the program stressed fundamental understanding of the mechanisms involved in friction and wear. Electron microscopy was used to elucidate the micromechanisms of wear following wear testing, and Auger electron spectroscopy was used to evaluate interface/environment interactions which seemed to be important in the friction and wear process. Unmodified ceramic sliding couples were characterized at all temperatures by friction coefficients of 0.24 and above. The coefficient at 800 C in an oxidizing environment was reduced to below 0.1, for certain material combinations, by the ion implanation of TiNi or Co. This beneficial effect was found to derive from lubricious Ti, Ni, and Co oxides.
Lankford, J.↗
Effect of Chemical Reactivity of Lubricant Additives on Friction and Surface Welding at High Sliding Velocities
Explore the source record for details and available documents.
BENZYL DISULPHIDE↗
Friction behavior of 304 stainless steel of varying hardness lubricated with benzene and some benzyl structures
The lubricating properties of some benzyl and benzene structures were determined by using 304 stainless steel surfaces strained to various hardness. Friction coefficients and wear track widths were measured with a Bowden-Leben type friction apparatus by using a pin-on-disk specimen configuration. Results obtained indicate that benzyl monosulfide, dibenzyl disulfide, and benzyl alcohol resulted in the lowest friction coefficients for 304 stainless steel, while benzyl ether provided the least surface protection and gave the highest friction. Strainhardening of the 304 stainless steel prior to sliding resulted in reduced friction in dry sliding. With benzyl monosulfide, dibenzyl disulfide, and benzyl alcohol changes in 304 stainless steel hardness had no effect upon friction behavior.
Buckley, D. H.↗
Friction and contact resistance for low-speed gallium-lubricated sliding electrical contacts of beryllium in vacuum
Reducing friction and contact resistance of sliding electrical contacts of beryllium by gallium lubrication in vacuum
Przybyszewski, J. S.↗
Sliding Wear and Fretting Wear of DLC-Based, Functionally Graded Nanocomposite Coatings
Improving the tribological functionality of diamondlike carbon (DLC) films--developing, good wear resistance, low friction, and high load-carrying capacity-was the aim of this investigation. Nanocomposite coatings consisting of an amorphous DLC (a-DLC) top layer and a functionally graded titanium-titanium carbon-diamondlike carbon (Ti-Ti(sub x) C(sub y)-DLC) underlayer were produced on AISI 440C stainless steel substrates by the hybrid technique of magnetron sputtering and pulsed-laser deposition. The resultant DLC films were characterized by Raman spectroscopy, scanning electron microscopy, and surface profilometry. Two types of wear experiment were conducted in this investioation: sliding friction experiments and fretting wear experiments. Unidirectional ball-on-disk sliding friction experiments were conducted to examine the wear behavior of an a-DLC/Ti-Ti(sub x) C(sub y)-DLC-coated AISI 440C stainless steel disk in sliding contact with a 6-mm-diameter AISI 440C stainless steel ball in ultrahigh vacuum, dry nitrogen, and humid air. Although the wear rates for both the coating and ball were low in all three environments, the humid air and dry nitrogen caused mild wear with burnishing, in the a-DLC top layer, and the ultrahigh vacuum caused relatively severe wear with brittle fracture in both the a-DLC top layer and the Ti-Ti(sub x) C(sub y)-DLC underlayer. For reference, amorphous hydrogenated carbon (H-DLC) films produced on a-DLC/Ti-Ti(sub x) C(sub y)-DLC nanocomposite coatings by using an ion beam were also examined in the same manner. The H-DLC films markedly reduced friction even in ultrahigh vacuum without sacrificing wear resistance. The H-DLC films behaved much like the a-DLC/Ti-Ti(sub x) C(sub y)-DLC nanocomposite coating in dry nitrogen and humid air, presenting low friction and low wear. Fretting wear experiments were conducted in humid air (approximately 50% relative humidity) at a frequency of 80 Hz and an amplitude of 75 micron on an a-DLC/Ti-Ti(sub x) C(sub y)-DLC-coated AISI 440C disk and on a titanium-6 wt % aluminum-4 wt% vanadium (Ti-6Al-4V) flat, both in contact with a 9.4-mm-diameter, hemispherical Ti-6Al-4V pin. The resistance to fretting wear and damage of the a-DLC/Ti-6Al-4V materials pair was superior to that of the Ti-6Al-4V/Ti-6AI-4V materials pair.
Miyoshi, K.↗
The friction and wear of ceramic/ceramic and ceramic/metal combinations in sliding contact
The tribological characteristics of ceramics sliding on ceramics are compared to those of ceramics sliding on a nickel based turbine alloy. The friction and wear of oxide ceramics and silicon-based ceramics in air at temperatures from room ambient to 900 C (in a few cases to 1200 C) were measured for a hemispherically-tipped pin on a flat sliding contact geometry. In general, especially at high temperature, friction and wear were lower for ceramic/metal combinations than for ceramic/ceramic combinations. The better tribological performance for ceramic/metal combinations is attributed primarily to the lubricious nature of the oxidized surface of the metal.
Sliney, Harold E.↗
The friction and wear of ceramic/ceramic and ceramic/metal combinations in sliding contact
The tribological characteristics of ceramics sliding on ceramics are compared to those of ceramics sliding on a nickel-based turbine alloy. The friction and wear of oxide ceramics and silicon-based ceramics in air at temperatures from room ambient to 900 C (in a few cases to 1200 C) were measured for a hemispherically-tipped pin on a flat sliding contact geometry. In general, especially at high temperature, friction and wear were lower for ceramic/metal combinations than for ceramic/ceramic combinations. The better tribological performance for ceramic/metal combinations is attributed primarily to the lubricious nature of the oxidized surface of the metal.
Sliney, Harold E.↗
Surface temperatures in sliding systems - A finite element analysis
Finite element equations are developed for studying surface temperatures resulting from frictional heating in sliding systems. The equations include the effect of velocity of moving components, an effect which is found to be quite significant, even at low sliding velocities. A program was written using the equations and it was applied to the study of surface temperatures in two different sliding systems: dry or boundary lubricated sleeve bearings and a labyrinth gas path seal configuration. Very good agreement was achieved between analytical predictions using the program and experimental temperature measurements. The program was used to study the influence of various material parameters on surface temperatures in the two sliding systems.
Kennedy, F. E., Jr.↗