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Surface Topography
Surface finish, also known as surface texture or surface topography, is the nature of a surface as defined by the three characteristics of lay, surface roughness, and waviness.. It comprises the small, local deviations of a surface from the perfectly flat ideal (a true plane). Surface texture is one of the important factors that control friction and transfer layer formation during sliding. Considerable efforts have been made to study the influence of surface texture on friction and wear during sliding conditions. Surface textures can be isotropic or anisotropic. Sometimes, stick-slip friction phenomena can be observed during sliding, depending on surface texture. Each manufacturing process (such as the many kinds of machining) produces a surface texture. The process is usually optimized to ensure that the resulting texture is usable. If necessary, an additional process will be added to modify the initial texture. The latter process may be grinding (abrasive cutting), polishin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interface (matter)
In the physical sciences, an interface is the boundary between two spatial regions occupied by different matter, or by matter in different physical states. The interface between matter and air, or matter and vacuum, is called a surface, and studied in surface science. In thermal equilibrium, the regions in contact are called phases, and the interface is called a phase boundary. An example for an interface out of equilibrium is the grain boundary in polycrystalline matter. The importance of the interface depends on the type of system: the bigger the quotient area/volume, the greater the effect the interface will have. Consequently, interfaces are very important in systems with large interface area-to-volume ratios, such as colloids. Interfaces can be flat or curved. For example, oil droplets in a salad dressing are spherical but the interface between water and air in a glass of water is mostly flat. Surface tension is the physical property which rules interface processes involvin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lithography
Lithography () is a planographic method of printing originally based on the immiscibility of oil and water. The printing is from a stone (lithographic limestone) or a metal plate with a smooth surface. It was invented in 1796 by the German author and actor Alois Senefelder and was initially used mostly for musical scores and maps.Meggs, Philip B. A History of Graphic Design. (1998) John Wiley & Sons, Inc. p 146 Carter, Rob, Ben Day, Philip Meggs. Typographic Design: Form and Communication, Third Edition. (2002) John Wiley & Sons, Inc. p 11 Lithography can be used to print text or images onto paper or other suitable material. A lithograph is something printed by lithography, but this term is only used for fine art prints and some other, mostly older, types of printed matter, not for those made by modern commercial lithography. Originally, the image to be printed was drawn with a greasy substance, such as oil, fat, or wax onto the surface of a smooth and flat limestone pla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Structured Light
A structured light pattern designed for surface inspection An Automatix Seamtracker arc welding robot equipped with a camera and structured laser light source, enabling the robot to follow a welding seam automatically Structured light is the process of projecting a known pattern (often grids or horizontal bars) on to a scene. The way that these deform when striking surfaces allows vision systems to calculate the depth and surface information of the objects in the scene, as used in structured light 3D scanners. ''Invisible'' (or ''imperceptible'') structured light uses structured light without interfering with other computer vision tasks for which the projected pattern will be confusing. Example methods include the use of infrared light or of extremely high frame rates alternating between two exact opposite patterns. Structured light is used by a number of police forces for the purpose of photographing fingerprints in a 3D scene. Where previously they would use tape to extract ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Focus Variation
Focus variation is a method used to sharpen images and to measure surface irregularities by means of optics with limited depth of field. Algorithm The algorithm work as follows: # at first images with difference focus are captured. This is done by moving the sample or the optics in relation to each other. # then for each position the focus over each plane is calculated # the plane with the best focus is used to get a sharp image. the corresponding depth gives the depth at this position- Optics Focus variation requires an optics with very little depth of field. This can be realized if a microscopy like optics and a microscope objective is used. These objectives have a high numerical aperture which gives a small depth of field. Usage The use of this method is for optical surface metrology and coordinate-measuring machine A coordinate measuring machine (CMM) is a device that measures the geometry of physical objects by sensing discrete points on the surface of the object with a p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Confocal Microscopy
Confocal microscopy, most frequently confocal laser scanning microscopy (CLSM) or laser confocal scanning microscopy (LCSM), is an optical imaging technique for increasing optical resolution and contrast of a micrograph by means of using a spatial pinhole to block out-of-focus light in image formation. Capturing multiple two-dimensional images at different depths in a sample enables the reconstruction of three-dimensional structures (a process known as optical sectioning) within an object. This technique is used extensively in the scientific and industrial communities and typical applications are in life sciences, semiconductor inspection and materials science. Light travels through the sample under a conventional microscope as far into the specimen as it can penetrate, while a confocal microscope only focuses a smaller beam of light at one narrow depth level at a time. The CLSM achieves a controlled and highly limited depth of field. Basic concept The principle of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interferometry
Interferometry is a technique which uses the '' interference'' of superimposed waves to extract information. Interferometry typically uses electromagnetic waves and is an important investigative technique in the fields of astronomy, fiber optics, engineering metrology, optical metrology, oceanography, seismology, spectroscopy (and its applications to chemistry), quantum mechanics, nuclear and particle physics, plasma physics, remote sensing, biomolecular interactions, surface profiling, microfluidics, mechanical stress/strain measurement, velocimetry, optometry, and making holograms. Interferometers are devices that extract information from interference. They are widely used in science and industry for the measurement of microscopic displacements, refractive index changes and surface irregularities. In the case with most interferometers, light from a single source is split into two beams that travel in different optical paths, which are then combined again to produce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Profilometer
A profilometer is a measuring instrument used to measure a surface's profile, in order to quantify its roughness. Critical dimensions as step, curvature, flatness are computed from the surface topography. While the historical notion of a profilometer was a device similar to a phonograph that measures a surface as the surface is moved relative to the contact profilometer's stylus, this notion is changing with the emergence of numerous non-contact profilometry techniques. Non-scanning technologies are able to measure the surface topography within a single camera acquisition, XYZ scanning is no longer needed. As a consequence, dynamic changes of topography are measured in real-time. Contemporary profilometers are not only measuring static topography, but now also dynamic topography – such systems are described as time-resolved profilometers. Types Optical methodsJean M. Bennett, Lars Mattsson, Introduction to Surface Roughness and Scattering, Optical Society of America, Was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stylus
A stylus (plural styli or styluses) is a writing utensil or a small tool for some other form of marking or shaping, for example, in pottery. It can also be a computer accessory that is used to assist in navigating or providing more precision when using touchscreens. It usually refers to a narrow elongated staff, similar to a modern ballpoint pen. Many styluses are heavily curved to be held more easily. Another widely used writing tool is the stylus used by blind users in conjunction with the slate for punching out the dots in Braille. Etymology The English word ''stylus'' has two plurals: ''styli'' and ''styluses''. The original Latin word was spelled ; the spelling ''stylus'' arose from an erroneous connection with Greek (), 'pillar'.'' Oxford Latin Dictionary'', s.v. "stilus" (2012). The Latin word had several meanings, including "a long, sharply pointed piece of metal; the stem of a plant; a pointed instrument for incising letters; the stylus (as used in literary co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mechanical Filtering Of Surface Finish Trace
Mechanical may refer to: Machine * Machine (mechanical), a system of mechanisms that shape the actuator input to achieve a specific application of output forces and movement * Mechanical calculator, a device used to perform the basic operations of arithmetic * Mechanical energy, the sum of potential energy and kinetic energy * Mechanical system, a system that manages the power of forces and movements to accomplish a task * Mechanism (engineering), a portion of a mechanical device Other * Mechanical (character), one of several characters in Shakespeare's ''A Midsummer Night's Dream'' * A kind of typeface in the VOX-ATypI classification See also * Machine, especially in opposition to an electronic item * ''Mechanical Animals'', the third full-length studio release by Marilyn Manson * Manufactured or artificial, especially in opposition to a biological or natural component * Automation, using machine decisions and processing instead of human * Mechanization, using machine labor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Machining Vibrations
Machining vibrations, also called chatter, are the relative movement between the workpiece and the cutting tool. The vibrations result in waves on the machined surface. This affects typical machining processes, such as turning, milling and drilling, and atypical machining processes, such as grinding. A chatter mark is an irregular surface flaw left by a wheel that is out of true in grinding or regular mark left when turning a long piece on a lathe, due to machining vibrations. As early as 1907, Frederick W. Taylor described machining vibrations as the most obscure and delicate of all the problems facing the machinist, an observation still true today, as shown in many publications on machining. The explanation of the machine tool regenerative chatter was made by Tobias. S. A. and W. Fishwick in 1958, by modeling the feedback loop between the metal cutting process and the machine tool structure, and came with the stability lobes diagram. The structure stiffness, damping ratio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wood Warping
Wood warping is a deviation from flatness in timber as a result of stresses and uneven shrinkage. Warping can also occur in wood considered "dry" (wood can take up and release moisture indefinitely), when it takes up moisture unevenly, or – especially – is allowed to return to its "dry" equilibrium state unevenly, too slowly, or too quickly. Many factors can contribute to wood warp: wood species, grain orientation, air flow, sunlight, uneven finishing, temperature – even cutting season and the moon's gravitational pull are taken into account in some traditions (e.g., violin making). The types of wood warping include: * bow: a warp along the length of the face of the wood * crook: a warp along the length of the edge of the wood * kink: a localized crook, often due to a knot * cup: a warp across the width of the face, in which the edges are higher or lower than the center of the wood * twist or wind: a distortion in which the two ends do not lie on the same plane. Winding s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rope
A rope is a group of yarns, plies, fibres, or strands that are twisted or braided together into a larger and stronger form. Ropes have tensile strength and so can be used for dragging and lifting. Rope is thicker and stronger than similarly constructed cord, string, and twine. Construction Rope may be constructed of any long, stringy, fibrous material, but generally is constructed of certain natural or synthetic fibres. Synthetic fibre ropes are significantly stronger than their natural fibre counterparts, they have a higher tensile strength, they are more resistant to rotting than ropes created from natural fibres, and they can be made to float on water. But synthetic ropes also possess certain disadvantages, including slipperiness, and some can be damaged more easily by UV light. Common natural fibres for rope are Manila hemp, hemp, linen, cotton, coir, jute, straw, and sisal. Synthetic fibres in use for rope-making include polypropylene, nylon, polyes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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