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in subjects: "Tribology"

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Variation of nominal contact pressure with time during sliding wear.

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Date: April 9, 2001

Creator: Ajayi, O. O. & Erck, R. A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Effect of carbon coating on scuffing performance in diesel fuels

Low-sulfur and low-aromatic diesel fuels are being introduced in order to reduce various types of emissions in diesel engines to levels in compliance with current and impending US federal regulations. The low lubricity of these fuels, however, poses major reliability and durability problems for fuel injection components that depend on diesel fuel for their lubrication. In the present study, the authors evaluated the scuff resistance of surfaces in regular diesel fuel containing 500 ppm sulfur a… more

Date: June 29, 2000

Creator: Ajayi, O. O.; Alzoubi, M. F.; Erdemir, A. & Fenske, G. R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Tribological performance of NFC coatings under oil lubrication[Near Frictionless Carbon]

An increase in engine and vehicle efficiency usually requires an increase in the severity of contact at the interfaces of many critical components. Examples of such components include piston rings and cylinder liners in the engine, gears in the transmission and axle, bearings, etc. These components are oil-lubricated and require enhancement of their tribological performance. Argonne National Laboratory (ANL) recently developed a carbon-based coating with very low friction and wear properties. T… more

Date: January 20, 2000

Creator: Ajayi, O. O.; Alzoubi, M.; Erdemir, A.; Fenske, G. R.; Eryilmaz, O. L. & Zimmerman, S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Tribological behavior of oil-lubricated, TiN-coated steel

The effects of titanium nitride (TiN) coatings on the tribological behavior of M50 and 52100 steels under both dry and synthetic polyol ester-based oil lubrication were evaluated using a reciprocating sliding pin-on-flat test machine. Under dry conditions, the TiN coating reduced the wear, which occurred by abrasion as well as the oxidation of the sliding surface. It also reduced the amount of wear-debris accumulation at the contact interface. During oil lubrication, wear and roughening of the … more

Date: February 1, 1992

Creator: Ajayi, O. O.; Erdemir, A.; Fenske, G. R.; Nichols, F. A.; Sproul, W. D.; Graham, M. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

The role of soft (metallic) film in tribological behavior of ceramic materials

The friction coefficient and wear rate in structural ceramic materials are often too high to make them attractive for applications requiring dry sliding. The role of a thin soft silver film in improving the tribological characteristics of silicon nitride materials is investigated in this study. In a pin-on-disc contact configuration in reciprocating motion, the friction coefficient was reduced by about 50% and the wear rate by one to two orders of magnitude. The friction reduction is thought to… more

Date: January 1, 1990

Creator: Ajayi, O.O.; Erdemir, A.; Erck, R.A.; Fenske, G.R. & Nichols, F.A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Tribological behavior of oil-lubricated, TiN-coated steel

Date: February 1, 1992

Creator: Ajayi, O.O.; Erdemir, A.; Fenske, G.R.; Nichols, F.A. (Argonne National Lab., IL (United States)); Sproul, W.D.; Graham, M. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Tribological behavior of near-frictionless carbon coatings in high- and low-sulfur diesel fuels.

The sulfur content in diesel fuel has a significant effect on diesel engine emissions, which are currently subject to environmental regulations. It has been observed that engine particulate and gaseous emissions are directly proportional to fuel sulfur content. With the introduction of low-sulfur fuels, significant reductions in emissions are expected. The process of sulfur reduction in petroleum-based diesel fuels also reduces the lubricity of the fuel, resulting in premature failure of fuel i… more

Date: January 19, 2000

Creator: Alzoubi, M. F.; Ajayi, O. O.; Eryilmaz, O. L.; Ozturk, O.; Erdemir, A. & Fenske, G.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Ultrathin ta-C films on heads depositied by twist-filteredcathodic arc carbon plasmas

It is known that filtered cathodic-arc-deposited ta-C films have outstanding properties even within the family of diamondlike materials. However, filtering of macroparticles is usually incomplete or accompanied by significant plasma losses. Ongoing research effort is directed towards the following goals: (1) complete elimination of macro- and nanoparticles from the vacuum arc plasma, (2) increase of plasma utilization in the cathodic-arc and macroparticle-filter system, (3) precise control and … more

Date: July 14, 2000

Creator: Anders, Andre & Ryan, Francis W.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Application of cathodic arc deposited amorphous hard carbon films to the head/disk tribology

Amorphous hard carbon films deposited by filtered cathodic arc deposition exhibit very high hardness and elastic modulus, high mass density, low coefficient of friction, and the films are very smooth. All these properties are beneficial to applications of these films for the head/disk interface tribology. The properties of cathodic arc deposited amorphous carbon films are summarized, and they are compared to sputter deposited, hydrogenated (CH{sub x}), and nitrogenated (CN{sub x}) carbon films … more

Date: April 1998

Creator: Anders, S.; Bhatia, C. S.; Fong, W.; Lo, R. Y. & Bogy, D. B.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Frictional behavior of diamondlike carbon films in vacuum and under varying water vapor pressure.

In this study, we investigated the frictional behavior of both hydrogenated and hydrogen-free diamondlike carbon (DLC) films in high vacuum (10{sup -6} Pa) at room temperature. Water was also introduced into the vacuum chamber to elucidate its effects on DLC film tribology. The hydrogen-free DLC (also referred to as tetrahedral amorphous carbon, or ta-C) was produced by an arc-PVD process, and the highly hydrogenated DLC was produced by plasma-enhanced chemical-vapor deposition. Tribological me… more

Date: March 25, 2002

Creator: Andersson, J.; Erck, R. A. & Erdemir, A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Study of the Interactions Between Friction, Wear and System Rigidity. Progress Report, July 1, 1979-June 30, 1980

Progress in friction and wear studies is reported. After an extensive study of various possible systems for friction, wear and vibration measurements, a pin and disk sliding system has been designed to be used on a rigid lathe bed. This versatile design has the capability of controlling the applied load, rigidity and damping of the total frictional system. The design and construction of the pin holding assembly has been completed with certain features to render it suitable for acquisition of ap… more

Date: March 1, 1980

Creator: Aronov, V.; D'Souza, A.F.; Kalpakjian, S. & Shareef, I.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Science and technology of ultrananocrystalline diamond (UNCD) thin films for multifunctional devices.

MEMS devices are currently fabricated primarily in silicon because of the available surface machining technology. However, Si has poor mechanical and tribological properties, and practical MEMS devices are currently limited primarily to applications involving only bending and flexural motion, such as cantilever accelerometers and vibration sensors, However, because of the poor flexural strength and fracture toughness of Si, and the tendency of Si to adhere to hydrophyllic surfaces, even these s… more

Date: November 15, 2000

Creator: Auciello, O.; Gruen, D. M.; Krauss, A. R.; Jayatissa, A.; Sumant, A.; Tucek, J. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Meso-scale machining capabilities and issues

Meso-scale manufacturing processes are bridging the gap between silicon-based MEMS processes and conventional miniature machining. These processes can fabricate two and three-dimensional parts having micron size features in traditional materials such as stainless steels, rare earth magnets, ceramics, and glass. Meso-scale processes that are currently available include, focused ion beam sputtering, micro-milling, micro-turning, excimer laser ablation, femto-second laser ablation, and micro elect… more

Date: May 15, 2000

Creator: BENAVIDES,GILBERT L.; ADAMS,DAVID P. & YANG,PIN

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Preparation and friction characteristics of self-lubricating TiN- MoS{sub 2} composite coatings

Composite coatings consisting of distinctly discrete phases of TiN and MoS{sub 2} were codeposited on graphite and Ti-6Al-4V substrates from Ti((CH3)2N)4/NH3/MoF6/H2S gas mixtures. Chemical composition and microstructure of the coatings were studied by Auger electron spectroscopy, XRD, and TEM. Friction coefficients at room temperature in air were typically in the range of 0.07 to 0.3; they remained comparable at 573 K, but increased to 0.7 to 1.0 at 673 K. A friction coefficient of {similar_to… more

Date: December 31, 1995

Creator: Bae, Y.W.; Lee, W.Y.; Besmann, T.M.; Yust, C.S. & Blau, P.J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Tribology studies of organic thin films by scanning force microscopy

The use of organic thin films as lubricants on solid surfaces is important in many modern technologies including magnetic storage and micromachines. Langmuir-Blodgett (LB) films and self-assembled monolayers (SAMs) are attractive candidates for lubricant layers and for model studies of lubrication because of their strong adsorption to the surface. The recent interest on the properties of LB films and SAMs has been also motivated by their potential applications in sensors, non-linear optical dev… more

Date: June 1, 1996

Creator: Bar, G.; Rubin, S.; Parikh, A.N.; Swanson, B.I. & Zawodzinski, T.A.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Development of Replacements for Phoscoating Used in Forging, Extrusion and Metal Forming Processes

Many forging, extrusion, heading and other metal forming processes use graphite-based lubricants, phosphate coatings, and other potentially hazardous or harmful substances to improve the tribology of the metal forming process. The application of phosphate-based coatings has long been studied to determine if other synthetic ''clean'' lubricants could provide the same degree of protection afforded by phoscoatings and its formulations. So far, none meets the cost and performance objectives provide… more

Date: March 1, 2003

Creator: Barnett, Kerry

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Editorial: Superlubricity across the scales

Article talks about how while the idea of frictionless surfaces and the associated implications of vanishing energy losses during mechanical motion have been part of science fiction culture, scientists in the real world work toward realizing this ambitious goal that was once thought to be unattainable. The overarching goal of the research topic titled “Superlubricity Across the Scales” is to provide a snapshot of the latest developments in this rapidly accelerating field of research.

Date: October 26, 2022

Creator: Baykara, Mehmet Z.; Berman, Diana & Rosenkranz, Andreas

Item Type: Article

Partner: UNT College of Engineering

open access

Molecular dynamics simulation of mechanical deformation of ultra-thin metal and ceramic films

We present an overview of the molecular dynamics computer simulation method as employed in the study of the mechanical properties of surfaces at the manometer scale. The embedded atom method is used to model a clean metal surface and the bond-order model is used to model ceramic surfaces. The computer experiment consists of the indentation and scraping of a hard diamond-like tool into and across the surface. Results are presented for the (111) surface of copper and silver and for the (100) surf… more

Date: April 1, 1995

Creator: Belak, J.; Glosli, J. N.; Boercker, D. B. & Stowers, I. F.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

The effect of prolonged exposure to 750{degree}C air on the tribological performance of PM212

The effect of prolonged exposure to 750C air on tribological performance and dimensional stability of PM212, a high temperature, self-lubricating composite, is studied. PM212, contains 70% metal-bonded Cr{sub 3}C{sub 2}, 15% BaF{sub 2}/CaF{sub 2} eutectic and 15% silver. Rub blocks were fabricated from PM212 by cold isostatic pressing followed by sintering. Prior to tribo-testing, the rub blocks were exposed to 750C air from 100 to 1000 hours. Then, the rub blocks were slid against nickel-based… more

Date: May 1, 1994

Creator: Bemis, K.; Bogdanski, M. S.; DellaCorte, C. & Sliney, H. E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Tribological Characteristics of sputtered Au/Cr films on alumina substrates at elevated temperatures

This paper describes research to evaluate the tribological properties of alumina pins sliding against thin sputtered gold films deposited on alumina disk substrates. A 250 {angstrom} thick chromium interlayer was first deposited onto the alumina test disks to enhance adhesion and high temperature wetting of the gold films. The Au/Cr films were tribotested in pure sliding in a pin-on-disk tribometer under a 4.9 N load at 1 m/s. The test atmosphere was room air at temperatures of 25, 500, and 800… more

Date: December 31, 1993

Creator: Benoy, P.A. & DellaCorte, C.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Materials technology at Argonne National Laboratory

Argonne is actively involved in the research and development of new materials research and development (R D). Five new materials technologies have been identified for commercial potential and are presented in this paper as follows: (1) nanophase materials, (2) nuclear magnetic resonance (NMR) imaging of ceramics, (3) superconductivity developments and technology transfer mechanisms, and (4) COMMIX computer code modeling for metal castings, and (5) tribology using ion-assisted deposition (IAB). … more

Date: January 1, 1989

Creator: Betten, P.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Ultra-thin overcoats for the head/disk interface tribology

Areal density in magnetic storage is increasing at a blistering pace of 60% annually. Recently IBM announced its mobile product with the industry highest areal density of 2.64 Gb/In{sup 2}. The areal density demonstrations have shown up to 5 Gb/In{sup 2} possible. Reaching higher areal density targets dictate that magnetic spacing between heads and disks be reduced. For the example of a 10 Gb/In{sup 2} areal density goal, the magnetic spacing should be {approx}25 nm. In budgeting this magnetic … more

Date: May 1997

Creator: Bhatia, C. S.; Anders, S. & Brown, I. G.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Friction of self-lubricating surfaces by ion beam techniques. Final technical report

UES, Inc. conducted a research and development program designed to establish conditions for ion implantation/mixing of suitable additives into the surfaces of bulk ceramics and metals for obtaining self-lubricating low friction and wear characteristics. The substrates considered were ZrO{sub 2}, Al{sub 2}O{sub 3}, Si{sub 3}N{sub 4}, steel and Ni-base superalloy. The lubricant additives chosen were BaF{sub 2}/CaF{sub 2}Ag, MoS{sub 2}, WS{sub 2}and B{sub 2}O{sub 3}. The initial tasks of the progr… more

Date: May 1, 1992

Creator: Bhattacharya, R. S. & Rai, A. K.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Friction microprobe investigation of particle layer effects on sliding friction

Interfacial particles (third-bodies), resulting from wear or external contamination, can alter and even dominate the frictional behavior of solid-solid sliding in the absence of effective particle removal processes (e.g., lubricant flow). A unique friction microprobe, developed at Oak Ridge National Laboratory, was used to conduct fine- scale friction studies using 1.0 mm diameter stainless steel spheres sliding on several sizes of loose layers of fine aluminum oxide powders on both aluminum an… more

Date: January 1, 1993

Creator: Blau, P. J.

Item Type: Report

Partner: UNT Libraries Government Documents Department