Download or read book Surface Chemistry and Superlubricity of Diamond like Carbon written by Ala' Al-azizi and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Contrary to the widely accepted idea that diamond-like carbon (DLC) is inert, this thesis provides evidence that DLC readily reacts with its surrounding environments. Reactions occurring at the surface of DLC strongly affect its surface composition and structure, and consequently, its friction and wear behavior. However, experimental results presented in this thesis show that reactivity of DLC is neither limited to, nor exclusively dictated by the surface. The bulk can both influence the reactivity of DLC, and be altered by it. The ultra-low friction behavior of DLC consists of three main components: the run-in behavior, transfer film formation, and the ultra-low steady friction. Our results prove that the cause of the run in behavior in dry environments is the removal of oxide layers of DLC. These oxide layers do not only have higher oxygen content, but are also richer in sp2 graphitic rings compared to the bulk of DLC. This structure reduces the wear resistance of the oxide layers, causing their removal and the high friction at the beginning of sliding in inert environments. In the presence of multi adsorbed water layers that can act as an electrolyte, this sp2 rich oxide protects DLC from wear when slid against more anodic surfaces. Although the oxide layer is just few nanometers thick and more susceptible to wear, they can induce galvanic corrosion on much harder counter surfaces protecting DLC during sliding in high humidity environments. Our results also indicate that the transfer film, another component often thought to be critical for the ultra-low friction of DLC, is a byproduct of internal stresses of DLC film, rather than requirement to achieve ultra-low friction. Mitigation of internal stresses of DLC improved its wear resistance and suppressed transfer film formation from DLC to the counter-surface. Our results also suggest that these internal stresses play a critical role in the susceptibility of the bulk to react with vapor molecules. Modifying DLC surface using vapor-phase reactions is often accompanied by reaction of the subsurface layers which negatively impacts the integrity of DLC network and its mechanical properties. Oxidation is detrimental to the ultra-low steady state friction, the third component of the friction behavior of DLC in inert environment. A chemical modification method using vapor-phase reaction with silanes to increase the hydrophobicity of DLC is developed and tested. Silane-treated DLC exhibits low friction in humid environments containing up to 30% water partial pressure. However, the silane treatment compromised the bulk properties of DLC reducing its wear resistance at water partial pressures of 40% and higher.
Download or read book Superlubricity written by Ali Erdemir and published by Elsevier. This book was released on 2020-09-22 with total page 575 pages. Available in PDF, EPUB and Kindle. Book excerpt: Superlubricity - the state between sliding systems where friction is reduced to almost immeasurable amounts - holds great potential for improving both the economic and environmental credentials of moving mechanical systems. Research in this field has progressed tremendously in recent years, and there now exist several theoretical models, recognised techniques for computational simulations and interesting experimental evidence of superlubricity in practise. Superlubricity, Second Edition, presents an extensively revised and updated overview of these important developments, providing a comprehensive guide to the physical chemistry underpinning molecular mechanisms of friction and lubrication, current theoretical models used to explore and assess superlubricity, examples of its achievement in experimental systems, and discussion of potential future applications. Drawing on the extensive knowledge of its expert editors and global team of authors from across academia and industry, Superlubricity, Second Edition, is a great resource for all those with a need to understand, model or manipulate surface interactions for improved performance. Fully expanded and updated to include the latest developments in the field, including a new section on liquid superlubricity Highlights the key superlubricity theoretical models and reviews state of the art tools and techniques for superlubricity simulation Includes information on the practical aspects and potential impact of superlubricity in moving mechanical systems ranging from nano/micro scales to meso/macro scales
Download or read book Tribology of Diamond like Carbon Films written by Christophe Donnet and published by Springer Science & Business Media. This book was released on 2007-12-06 with total page 673 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book highlights some of the most important structural, chemical, mechanical and tribological characteristics of DLC films. It is particularly dedicated to the fundamental tribological issues that impact the performance and durability of these coatings. The book provides reliable and up-to-date information on available industrial DLC coatings and includes clear definitions and descriptions of various DLC films and their properties.
Download or read book Superlubricity written by Ali Erdemir and published by Elsevier. This book was released on 2007-03-30 with total page 525 pages. Available in PDF, EPUB and Kindle. Book excerpt: Superlubricity is defined as a sliding regime in which friction or resistance to sliding vanishes. It has been shown that energy can be conserved by further reducing/removing friction in moving mechanical systems and this book includes contributions from world-renowned scientists who address some of the most fundamental research issues in overcoming friction. Superlubricity reviews the latest methods and materials in this area of research that are aimed at removing friction in nano-to-micro scale machines and large scale engineering components. Insight is also given into the atomic-scale origins of friction in general and superlubricity while other chapters focus on experimental and practical aspects or impacts of superlubricity that will be very useful for broader industrial community. * Reviews the latest fundamental research in superlubricity today* Presents 'state-of-the-art' methods, materials, and experimental techniques* Latest developments in tribomaterials, coatings, and lubricants providing superlubricity
Download or read book Superlubricity and Wearless Sliding in Diamondlike Carbon Films written by and published by . This book was released on 2001 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt: Diamondlike carbon (DLC) films have attracted great interest in recent years mainly because of their unusual optical, electrical, mechanical, and tribological properties. Such properties are currently being exploited for a wide range of engineering applications including magnetic hard disks, gears, sliding and roller bearings, scratch resistant glasses, biomedical implants, etc. Systematic studies on carbon-based materials in our laboratory have led to the development of a new class of amorphous DLC films that provide extremely low friction and wear coefficients of 0.001 to 0.005 and 10−11 to 10−1° mm3 /N.m, respectively, when tested in inert-gas or high-vacuum environments. These films were produced in highly hydrogenated gas discharge plasmas by a plasma enhanced chemical vapor deposition process at room temperature. The carbon source gases used in the deposition of these films included methane, acetylene, and ethylene. Tribological studies in our laboratory have established a very close correlation between the composition of the plasmas and the friction and wear coefficients of the resultant DLC films. Specifically, the friction and wear coefficients of DLC films grown in plasmas with higher hydrogen-to-carbon ratios were much lower than films derived from source gases with lower hydrogen-to-carbon ratios. Fundamental tribological and surface analytical studies have led us to conclude that hydrogen (within the film, as well as on the sliding surfaces) is extremely important for the superlubricity and wearless sliding behavior of these films. Based on these studies, a mechanistic model is proposed to explain the superlow friction and wear properties of the new DLC films.
Download or read book Handbook of Carbon Graphite Diamonds and Fullerenes written by Hugh O. Pierson and published by William Andrew. This book was released on 2012-12-02 with total page 420 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a review of the science and technology of the element carbon and its allotropes: graphite, diamond and the fullerenes. This field has expanded greatly in the last three decades stimulated by many major discoveries such as carbon fibers, low-pressure diamond, and the fullerenes. The need for such a book has been felt for some time. These carbon materials are very different in structure and properties. Some are very old (charcoal), others brand new (the fullerenes). They have different applications and markets and are produced by different segments of the industry.Few studies are available that attempt to review the entire field of carbon as a whole discipline. Moreover these studies were written several decades ago and a generally outdated since the development of the technology is moving very rapidly and scope of applications is constantly expanding and reaching into new fields such as aerospace, automotive, semiconductors, optics, and electronics. In this book the author provides a valuable, up-to-date account of both the newer and traditional forms of carbon, both naturally occurring and man-made. This volume will be a valuable resource for both specialists in, and occasional users of carbon materials.
Download or read book Diamond Like Carbon Coatings written by Peerawatt Nunthavarawong and published by CRC Press. This book was released on 2022-08-08 with total page 329 pages. Available in PDF, EPUB and Kindle. Book excerpt: Diamond-like carbons (DLCs) display a number of attractive properties that make them versatile coating materials for a variety of applications, including extremely high hardness values, very low friction properties, very low gas permeability, good biocompatibility, and very high electrical resistivity, among others. Further research into this material is required to produce hydrogen-free DLC films and to synthesize it together with other materials, thereby obtaining better film properties. Diamond-Like Carbon Coatings: Technologies and Applications examines emerging manufacturing technologies for DLCs with the aim of improving their properties for use in practical applications. Discusses DLC coatings used in mechanical, manufacturing, and medical applications Details recent developments in the novel synthesis of DLC films Covers advances in understanding of chemical, structural, physical, mechanical, and tribological properties for modern material processing Highlights methods to yield longer service life Considers prospects for future applications of emerging DLC technologies This work is aimed at materials science and engineering researchers, advanced students, and industry professionals.
Download or read book Lubrication by Diamond and Diamondlike Carbon Coatings written by and published by . This book was released on 1997 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Aerospace Materials Handbook written by Sam Zhang and published by CRC Press. This book was released on 2016-04-19 with total page 763 pages. Available in PDF, EPUB and Kindle. Book excerpt: Whether an airplane or a space shuttle, a flying machine requires advanced materials to provide a strong, lightweight body and a powerful engine that functions at high temperature. The Aerospace Materials Handbook examines these materials, covering traditional superalloys as well as more recently developed light alloys. Capturing state-of-the-art d
Download or read book Coatings Tribology written by K. Holmberg and published by Elsevier. This book was released on 1994-07-15 with total page 457 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a general view on thin surface coatings used for tribological applications and it is based on the current state of understanding. The mechanisms of friction and wear in sliding and rolling contacts of coated surfaces are described. Basic information on coating techniques, tribology and surface mechanisms is given. Based on collected experimental works information is given on the properties of thin soft coatings, such as polymer, lamellar solid and soft metal coatings; thin hard coatings, such as nitride, carbide, oxide, boride and diamond and diamond-like coatings; and multi-component and multi-layer coatings. The influence of interface layers and lubricants is highlighted. The methods available for characterization of coated surfaces and for mechanical and chemical evaluation of their tribological properties are described. Tribological evaluation methods for accelerated and field testing and the need for standardization of quality assurance procedures are discussed. A methodology for the selection of thin coatings for tribological applications is presented and knowledge based expert system approaches for coating selection are reviewed. For different application examples, the basic tribological contact mechanisms are described and the possibilities for improving their tribological properties by using surface coatings are discussed. The application examples include sliding and rolling bearings, gears, tools for cutting and forming, erosion resistant applications, magnetic recording systems and bio-medical implants.
Download or read book Synthesis of Diamondlike Carbon Films with Superlow Friction and Wear Properties written by and published by . This book was released on 2000 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this study, the authors introduce a new diamondlike carbon (DLC) film providing a friction coefficient of 0.001 and wear rates of 10−9 to 10−1° mm3/N.m in inert-gas environments (e.g., dry nitrogen and argon). The film was grown on steel and sapphire substrates in a plasma enhanced chemical vapor deposition system that uses using a hydrogen-rich plasma. Employing a combination of surface and structure analytical techniques, they explored the structural chemistry of the resultant DLC films and correlated these findings with the friction and wear mechanisms of the films. The results of tribological tests under a 10-N load (creating initial peak Hertz pressures of 1 and 2.2 GPa on steel and sapphire test pairs, respectively) and at 0.2 to 0.5 m/s sliding velocities indicated that a close correlation exists between the friction and wear coefficients of DLC films and the source gas chemistry. Specifically, films grown in source gases with higher hydrogen-to-carbon ratios had the lowest fiction coefficients and the highest wear resistance. The lowest friction coefficient (0.001) was achieved with a film on sapphire substrates produced in a gas discharge plasma consisting of 25% methane and 75% hydrogen.
Download or read book Friction and Wear From Elementary Mechanisms to Macroscopic Behavior written by Valentin L. Popov and published by Frontiers Media SA. This book was released on 2019-08-21 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt: Friction and the interaction of surfaces can usually be felt at the scale of the contacting bodies. Indeed, phenomena such as the frictional resistance or the occurrence of wear can be observable with plain eye, but to characterize them and in order to make a prediction, a more detailed understanding at smaller scales is often required. These can include individual roughness peaks or single molecule interactions. In this Research Topic, we have gathered a collection of articles representing the state of the art in tribology’s endeavor to bridge the gap between nano scale elementary research and the macroscopic behavior of contacting bodies. These articles showcase the breadth of questions related to the interaction of micro and macro scale and give examples of successful transfer of insights from one to the other. We are delighted to present this Research Topic to the reader with the hope that it will further inspire and stimulate research in the field.
Download or read book Handbook of Research on Tribology in Coatings and Surface Treatment written by Pakseresht, Amirhossein and published by IGI Global. This book was released on 2022-03-25 with total page 470 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances are continuously being made in applying the coatings and surface treatments by different techniques to reduce the damages from tribology. Engineers need more detailed information to compare the capability of each coating process in wear resistant and lubrication applications. It is also important to focus on the concepts of tribology in various applications such as the manufacturing process, bio implants, machine elements, and corrosive environments. The need for a comprehensive resource addressing these findings in order to improve wear resistance is unavoidable. The Handbook of Research on Tribology in Coatings and Surface Treatment evaluates the latest advances the fabrication of wear-resistant and lubricant coatings by different techniques and investigates wear-resistant coatings and surface treatments in various applications such as the automobile industry. Covering a wide range of topics such as lubricant coatings and wearable electronic devices, it is ideal for engineers, industry professionals, researchers, academicians, scholars, practitioners, instructors, and students.
Download or read book Proceedings of Asia International Conference on Tribology 2018 written by Mohd Fadzli Bin Abdollah and published by Malaysian Tribology Society. This book was released on 2018-09-17 with total page 540 pages. Available in PDF, EPUB and Kindle. Book excerpt: This ebook is a compilation of 234 papers presented at the 6th Asia International Conference on Tribology (ASIATRIB2018): Kuching, Sarawak - Malaysia from 17 to 20 September 2018.
Download or read book Contact mechanics perspective of tribology written by Irina Goryacheva and published by Frontiers Media SA. This book was released on 2021-06-04 with total page 391 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Elasto Hydrodynamic Lubrication written by D. Dowson and published by Elsevier. This book was released on 2014-07-18 with total page 254 pages. Available in PDF, EPUB and Kindle. Book excerpt: Elasto-Hydrodynamic Lubrication deals with the mechanism of elasto-hydrodynamic lubrication, that is, the lubrication regime in operation over the small areas where machine components are in nominal point or line contact. The lubrication of rigid contacts is discussed, along with the effects of high pressure on the lubricant and bounding solids. The governing equations for the solution of elasto-hydrodynamic problems are presented. Comprised of 13 chapters, this volume begins with an overview of elasto-hydrodynamic lubrication and representation of contacts by cylinders, followed by a discussion on equations relevant to lubrication, including the Reynolds equation. The reader is then introduced to lubrication of rigid cylinders; the importance of film thickness in highly loaded rigid contacts; the elasticity of solids in contact; and the theory of elasto-hydrodynamic lubrication. Subsequent chapters focus on apparatus and measurements of film thickness and film shape; friction and viscosity; and lubrication of gears and roller bearings. This book will be of interest to tribologists.
Download or read book Tribology written by Jürgen Gegner and published by BoD – Books on Demand. This book was released on 2013-05-22 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt: As the subject of tribology comprises lubrication, friction and wear of contact components highly relevant to practical applications, it challenges scientists from chemistry, physics and materials engineering around the world on todays sophisticated experimental and theoretical foundation to complex interdisciplinary research. Recent results and developments are preferably presented and evaluated in the context of established knowledge. Consisting of eleven chapters divided into the four parts of Lubrication and Properties of Lubricants, Boundary Lubrication Applications, Testing and Modeling, and Sustainability of Tribosystems, this textbook therefore merges basic concepts with new findings and approaches. Tribology Fundamentals and Advancements, supported by competent authors, aims to convey current research trends in the light of the state of the art to students, scientists and practitioners and help them solve their problems.
