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Research & Tribology Studies RESEARCH & TRIBOLOGY STUDIES TRIBOLOGY STUDIES Tribology is defi ned as, “The science of APPLIED RESEARCH PROJECTS lubricant in use is critical to answering the mechanisms of friction, lubrication, complex tribological problems industry SGS Herguth Labs takes an active and wear of interacting surfaces that faces every day! If the lubrication in your leadership role in applying research to are in relative motion.” A great deal of system is mineral or synthetic oil, solid or many specialized projects. Called upon by tribological research is being conducted gas, SGS Herguth Labs can help you with oil company giants, our personnel pursue throughout the world in universities and your tribology needs. each case with innovation and initiation, in private, government, and industrial always focused on the ultimate solution. laboratories. Virtually unheard of ten FAILURE ANALYSIS OF LUBRICATED years ago, there have been thousands Tribology studies represent another COMPONENTS of Tribology papers published strength of SGS Herguth Labs. Our since 1990 and the knowledge is applied research team provides failure SGS Herguth Labs has complete disseminated through many technical analysis for clients throughout the world. resources available for Optical or Scanning societies. The reliability of machines On a local front, Folsom Dam asked a SGS Electron Microscopy, Photomicrography, steadily improves because of this Herguth Labs research associate for help Chemical Testing and Analysis by ICP, FT- research. after the seizure of a huge bearing on a IR, SEM/EDX, XRD or AES. fl ood gate caused the loss of thousands of acre-feet of water. We resolved the HIGH QUALITY REPORTS AND SPECIFIC SGS Herguth Laboratories and our problem of what lubricant to use in RECOMMENDATIONS TO HELP YOU SOLVE research associates are committed to their large bearing to prevent this from YOUR TRIBOLOGY PROBLEMS. maintaining our edge in tribology. Wear, or happening again. the undesirable removal of material due Beyond the oil company projects and At the opposing end of the size chart, yet to relative motion, is a large consumer our tribological studies, SGS Herguth with cost consequences of equivalent of materials, and shortens the life and Labs research and development arm is value, we were asked by Seagate to reduces the reliability of machines. Friction often called upon to set test programs analyze pencil-eraser size bearings, and wear cost the economies of the world to determine lubricant and grease looking for a lubricating grease to billions of dollars per year. specifi cations, including amounts of maximize service life. SGS Herguth Labs provides Tribological additives and other variables that have services as follows: an operational impact on equipment and UNDERSTANDING LUBRICATION machinery. Our applied research team can There are three lubrication operation set up and implement procedures to meet WEAR ANALYSIS modes or ‘regimes’, which are: your specifi c requirements and program • Determine mechanism of wear and goals. • Hydrodynamic Lubrication (HDL) - solutions by examination of worn SGS is the world’s leading inspection, HDL conditions exist when a gas parts verification, testing and certification or liquid fi lm completely separates company. Recognized as the global • Analysis of Lubricants moving surfaces and there is no solid- benchmark for quality and integrity, we to-solid contact. Example: automotive employ over 80 000 people and operate WEAR PARTICLE ANALYSIS main bearings. a network of more than 1 650 offices and PERFORMANCE TESTS • ElastoHydrodynamic Lubrication laboratories around the world. • “Pin-on-Disk” by ASTM G-99 (EHL) In the EHL regime, a complete oil fi lm remains between two SGS NORTH AMERICA INC. • 4-ball tests by ASTM D-1583, ASTM surfaces in elastic deformation. High D-2283 and ASTM D-4172 measure OIL, GAS AND CHEMICALS SERVICES localized pressures cause the oil friction and wear of metal/lubricant to ‘solidify.’ Examples: ball or roller SAN FRANCISCO combinations under boundary bearings. 101 Corporate Place lubrication conditions • Boundary Lubrication (BL) - Vallejo, CA 94590, USA • “Pad-on-Disk” Under conditions of high loads or CHICAGO AREA • Friction temperatures, low sliding velocities 1600 Shore Road, Suite H • Electrical contact under hydrodynamic and rough sliding surfaces, BL Naperville, IL, 60563 conditions conditions prevail. Example: screw threads. Toll Free: +1 800 645 5227 (OIL-LABS) • Ball bearing torque measurements Phone: +1 707 554 4611 Each of these lubrication regimes imposes • Fretting Corrosion tests for metal/ Fax: +1 707 554 0109 unique requirements on the lubricant. lubricant combinations Understanding the interaction of the WWW.SGS.COM/OILCONDITIONMONITORING metallurgy, the nature of machined WWW.SGS.COM/HERGUTH surfaces, wear mechanisms and the © SGS North America Inc – 2015 – All rights reserved - SGS is a registered trademark of Group Management SA – America Inc – 2015 © SGS North.
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  • Lubrication Chemistry Viewed from DFT-Based Concepts and Electronic Structural Principles
    Int. J. Mol. Sci. 2004, 5, 13-34 International Journal of Molecular Sciences ISSN 1422-0067 © 2004 by MDPI www.mdpi.org/ijms/ Lubrication Chemistry Viewed from DFT-Based Concepts and Electronic Structural Principles Li Shenghua*, Yang He and Jin Yuansheng State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, P.R. China Tel.: +86 (10) 62772509, Fax: +86 (10) 62784691, E-mail: [email protected] URL: http://www.pim.tsinghua.edu.cn/sklt/sklt.html *Author to whom correspondence should be addressed. Received: 16 April 2003 / Accepted: 16 October 2003 / Published: 26 December 2003 Abstract: Fundamental molecular issues in lubrication chemistry were reviewed under categories of solution chemistry, contact chemistry and tribochemistry. By introducing the Density Functional Theory(DFT)-derived chemical reactivity parameters (chemical potential, electronegativity, hardness, softness and Fukui function) and related electronic structural principles (electronegativity equalization principle, hard-soft acid-base principle, and maximum hardness principle), their relevancy to lubrication chemistry was explored. It was suggested that DFT, theoretical, conceptual and computational, represents a useful enabling tool to understand lubrication chemistry issues prior to experimentation and the approach may form a key step in the rational design of lubrication chemistry via computational methods. It can also be optimistically anticipated that these considerations will gestate unique DFT-based strategies to understand sophisticated tribology themes, such as origin of friction, essence of wear, adhesion in MEMS/NEMS, chemical mechanical polishing in wafer manufacturing, stress corrosion, chemical control of friction and wear, and construction of designer tribochemical systems. Keywords: Lubrication chemistry, DFT, chemical reactivity indices, electronic structural principle, tribochemistry, mechanochemistry.
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