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Tribology
Tribology is the science and engineering of understanding friction, lubrication and wear phenomena for interacting surfaces in relative Motion (physics), motion. It is highly interdisciplinary, drawing on many academic fields, including physics, chemistry, materials science, mathematics, biology and engineering. The fundamental objects of study in tribology are tribosystems, which are physical systems of contacting surfaces. Subfields of tribology include biotribology, nanotribology and space tribology. It is also related to other areas such as the coupling of corrosion and tribology in tribocorrosion and the contact mechanics of how surfaces in contact deform. Approximately 20% of the total energy expenditure of the world is due to the impact of friction and wear in the transportation, manufacturing, power generation, and residential sectors. Etymology The word ''tribology'' derives from the Ancient Greek, Greek root τριβ- of the verb , ''wiktionary:tribo-, tribo'', "I rub" in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peter Jost
(Hans) Peter Israel Jost, Companion of the Order of the British Empire, CBE (25 January 1921 – 7 June 2016) was a British mechanical engineer. He was the founder of the discipline of tribology, the science and engineering of interacting surfaces in relative motion. In 1966, Jost published a report which highlighted the cost of friction, wear and corrosion to the United Kingdom economy (1.1-1.4% of Gross domestic product, GDP). It was in this eponymous report that he coined the term tribology, which has now been widely adopted. Early life and education Jost was born in Berlin, son of merchant Leo Jost, and Margot (née Jacoby), both of Jewish descent. He was educated at Liverpool Technical College and Manchester Metropolitan University, Manchester College of Technology. Career Jost was an apprentice at Associated Metal Works, Glasgow, then at Napier and Sons in Liverpool, where he won the Sir John Larking medal for a paper on measurement of surface finish. At 29, he became gener ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wear
Wear is the damaging, gradual removal or deformation of material at solid surfaces. Causes of wear can be mechanical (e.g., erosion) or chemical (e.g., corrosion). The study of wear and related processes is referred to as tribology. Wear in machine elements, together with other processes such as fatigue and creep, causes functional surfaces to degrade, eventually leading to material failure or loss of functionality. Thus, wear has large economic relevance as first outlined in the Jost Report. Abrasive wear alone has been estimated to cost 1–4% of the gross national product of industrialized nations. Wear of metals occurs by plastic displacement of surface and near-surface material and by detachment of particles that form wear debris. The particle size may vary from millimeters to nanometers. This process may occur by contact with other metals, nonmetallic solids, flowing liquids, solid particles or liquid droplets entrained in flowing gasses. The wear rate is affected ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Friction
Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other. Types of friction include dry, fluid, lubricated, skin, and internal -- an incomplete list. The study of the processes involved is called tribology, and has a history of more than 2000 years. Friction can have dramatic consequences, as illustrated by the use of friction created by rubbing pieces of wood together to start a fire. Another important consequence of many types of friction can be wear, which may lead to performance degradation or damage to components. It is known that frictional energy losses account for about 20% of the total energy expenditure of the world. As briefly discussed later, there are many different contributors to the retarding force in friction, ranging from asperity deformation to the generation of charges and changes in local structure. When two bodies in contact move relative to each other, due to these variou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lubrication
Lubrication is the process or technique of using a lubricant to reduce friction and wear and tear in a contact between two surfaces. The study of lubrication is a discipline in the field of tribology. Lubrication mechanisms such as fluid-lubricated systems are designed so that the applied load is partially or completely carried by hydrodynamic or hydrostatic pressure, which reduces solid body interactions (and consequently friction and wear). Depending on the degree of surface separation, different lubrication regimes can be distinguished. Adequate lubrication allows smooth, continuous operation of machine elements, reduces the rate of wear, and prevents excessive stresses or seizures at bearings. By repelling water and other substances, it also reduces corrosion. When lubrication breaks down, components can rub destructively against each other, causing heat, local welding, destructive damage and failure. Lubrication mechanisms Fluid-lubricated systems As the load incre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guillaume Amontons
Guillaume Amontons (31 August 1663 – 11 October 1705) was a French scientific instrument inventor and physicist. He was one of the pioneers in studying the problem of friction, which is the resistance to motion when bodies make contact. He is also known for his work on thermodynamics, the concept of absolute zero, and early engine design. Life Guillaume was born in Paris, France. His father was a lawyer from Normandy who had moved to the French capital. While still young, Guillaume lost his hearing and became mostly deaf. According to one biographer, Fontenelle, while studying perpetual motion, he became convinced of the importance of studying machines from a mathematical perspective. He never attended a university, but was able to study mathematics, the physical sciences, and celestial mechanics. He also spent time studying the skills of drawing, surveying, and architecture. He died in Paris, France. Work He was supported in his research career by the government, and was e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Contact Mechanics
Contact mechanics is the study of the Deformation (mechanics), deformation of solids that touch each other at one or more points. A central distinction in contact mechanics is between Stress (mechanics), stresses acting perpendicular to the contacting bodies' surfaces (known as normal stress) and frictional stresses acting Tangential and normal components, tangentially between the surfaces (shear stress). Normal contact mechanics or frictionless contact mechanics focuses on normal stresses caused by applied normal forces and by the adhesion present on surfaces in close contact, even if they are clean and dry. ''Frictional contact mechanics'' emphasizes the effect of friction forces. Contact mechanics is part of mechanical engineering. The physical and mathematical formulation of the subject is built upon the mechanics of materials and continuum mechanics and focuses on computations involving Elasticity (physics), elastic, viscoelasticity, viscoelastic, and Plastic Deformation, p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Charles-Augustin De Coulomb
Charles-Augustin de Coulomb ( ; ; 14 June 1736 – 23 August 1806) was a French officer, engineer, and physicist. He is best known as the eponymous discoverer of what is now called Coulomb's law, the description of the electrostatic force of attraction and repulsion. He also did important work on friction, and his work on earth pressure formed the basis for the later development of much of the science of soil mechanics. The SI unit of electric charge, the coulomb, was named in his honor in 1880. Life Charles-Augustin de Coulomb was born in Angoulême, Angoumois county, France, to Henry Coulomb, an inspector of the royal demesne originally from Montpellier, and Catherine Bajet. He was baptised at the parish church of St. André. The family moved to Paris early in his childhood, and he studied at Collège Mazarin. His studies included philosophy, language and literature. He also received a good education in mathematics, astronomy, chemistry and botany. When his father suffer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leonardo Da Vinci
Leonardo di ser Piero da Vinci (15 April 1452 - 2 May 1519) was an Italian polymath of the High Renaissance who was active as a painter, draughtsman, engineer, scientist, theorist, sculptor, and architect. While his fame initially rested on his achievements as a painter, he has also become known for #Journals and notes, his notebooks, in which he made drawings and notes on a variety of subjects, including anatomy, astronomy, botany, cartography, painting, and palaeontology. Leonardo is widely regarded to have been a genius who epitomised the Renaissance humanism, Renaissance humanist ideal, and his List of works by Leonardo da Vinci, collective works comprise a contribution to later generations of artists matched only by that of his younger contemporary Michelangelo. Born out of wedlock to a successful notary and a lower-class woman in, or near, Vinci, Tuscany, Vinci, he was educated in Florence by the Italian painter and sculptor Andrea del Verrocchio. He began his career ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nanotribology
Nanotribology is the branch of tribology that studies friction, wear, adhesion and lubrication phenomena at the Nanoscopic scale, nanoscale, where atomic interactions and quantum effects are not negligible. The aim of this discipline is characterizing and modifying surfaces for both scientific and technological purposes. Nanotribological research has historically involved both direct and indirect methodologies. Microscopy techniques, including Scanning tunneling microscope, Scanning Tunneling Microscope (STM), Atomic-force microscopy, Atomic-Force Microscope (AFM) and Surface forces apparatus, Surface Forces Apparatus, (SFA) have been used to analyze surfaces with extremely high resolution, while indirect methods such as Molecular modelling, computational methods and Quartz crystal microbalance (QCM) have also been extensively employed. Changing the topology of surfaces at the nanoscale, friction can be either reduced or enhanced more intensively than macroscopic lubrication and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tribosystem
A tribosystem is a tribological system that consists of at least two contacting bodies and any environmental factor that affects their interaction. Tribologists study tribological systems in detail, and devise tribological test procedures. Definition According tASTM G40-17 a tribosystem is "any system that contains one or more triboelements, including all mechanical, chemical, and environmental factors relevant to tribological behavior." Here, ''triboelement'' refers to "one of two or more solid bodies that comprise a sliding, rolling, or abrasive contact, or a body subjected to impingement or cavitation." More simply speaking, a tribosystem is a tribological system that consists of at least two contacting bodies, including the environment in which the interaction takes place. The complete description of a tribosystem includes all relevant factors that govern the tribological behavior of the system. Thus, depending on the aim of the tribological analysis, the tribosystem boundar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Space Tribology
Space tribology is a discipline in the field of tribology which deals with tribological systems for spacecraft applications. Research in the field aims to design reliable tribological systems that can withstand the harsh environment of space. Challenges In addition to regular tribological stresses, machine elements for space applications need to withstand the harsh environment during launch and in orbit. In particular, critical tribosystem inputs are: * random vibrations and acoustic noise during launch, leading to high transient loads and high-frequency, low-amplitude motion that may cause fretting * extreme temperatures and temperature fluctuations, "ranging from cryogenic temperature to several hundred degrees Celsius". This may lead to drastic changes in material properties, especially in case of lubricants. * vacuum in the order of 10−7 to 10−13 mbar, leading to evaporation of lubricants. This can cause both lubrication failure and contamination of sensitive instrume ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tribocorrosion
Tribocorrosion is a material degradation process due to the combined effect of corrosion and wear. The name tribocorrosion expresses the underlying disciplines of tribology and corrosion. Tribology is concerned with the study of friction, lubrication and wear (its name comes from the Greek "tribo" meaning to rub) and corrosion is concerned with the chemical and electrochemical interactions between a material, normally a metal, and its environment. As a field of research tribocorrosion is relatively new, but tribocorrosion phenomena have been around ever since machines and installations are being used. Wear is a mechanical material degradation process occurring on rubbing or impacting surfaces, while corrosion involves chemical or electrochemical reactions of the material. Corrosion may accelerate wear and wear may accelerate corrosion. One then speaks of corrosion accelerated wear or wear accelerated corrosion. Both these phenomena, as well as fretting corrosion (which results fro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
