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49-566: Brasso is a metal polish designed to remove tarnish from brass , copper, chrome and stainless steel . It is available either directly as a liquid or as an impregnated wadding pad also known as Duraglit . Brasso originated in Britain in about 1905. Reckitt & Sons ' senior traveller, W. H. Slack, visited the company's Australian branch, where he discovered such a product in use. Samples from Australian and US producers were then analysed by Reckitt's chemists, and by 1920 liquid polish under

98-514: A clean, bright, shiny surface finish. This is achieved by moving the workpiece with the rotation of the buffing wheel, while using medium to light pressure. When polishing brass (a softer metal) there are often minute marks in the metal caused by impurities. To smooth out the finer marks, the surface is polished with a very fine (600) grit, copper plated , then buffed to a mirror finish with an airflow mop. Polishing operations for items such as chisels, hammers, screwdrivers, wrenches, etc., are given

147-411: A de-coppering agent in rifle barrels to remove copper fouling. Metal polish Polishing is often used to enhance the appearance of an item, prevent contamination of instruments, remove oxidation, create a reflective surface, or prevent corrosion in pipes. In metallography and metallurgy , polishing is used to create a flat, defect-free surface for examination of a metal's microstructure under

196-407: A diamond grit suspension which is dosed onto a reusable fabric pad throughout the polishing process. Diamond grit in suspension might start at 9 micrometres and finish at one micrometre. Generally, polishing with diamond suspension gives finer results than using silicon carbide papers (SiC papers), especially with revealing porosity , which silicon carbide paper sometimes "smear" over. After grinding

245-448: A fine finish but not plated. In order to achieve this finish four operations are required: roughing, dry fining, greasing, and coloring. Note that roughing is usually done on a solid grinding wheel and for an extra fine polish the greasing operation may be broken up into two operations: rough greasing and fine greasing. However, for inexpensive items money is saved by only performing the first two operations. Polishing knives and cutlery

294-493: A good microscope, it is possible to perform examination at higher magnifications, e.g., 2000X, and even higher, as long as diffraction fringes are not present to distort the image. However, the resolution limit of the LOM will not be better than about 0.2 to 0.3 micrometers. Special methods are used at magnifications below 50X, which can be very helpful when examining the microstructure of cast specimens where greater spatial coverage in

343-426: A microscope. Silicon-based polishing pads or a diamond solution can be used in the polishing process. Polishing stainless steel can also increase its sanitary benefits. The removal of oxidization (tarnish) from metal objects is accomplished using a metal polish or tarnish remover; this is also called polishing. To prevent further unwanted oxidization, polished metal surfaces may be coated with wax, oil, or lacquer. This

392-667: A proper statistical basis for the measurement. Efforts to eliminate bias are required. Some of the most basic measurements include determination of the volume fraction of a phase or constituent, measurement of the grain size in polycrystalline metals and alloys, measurement of the size and size distribution of particles, assessment of the shape of particles, and spacing between particles. Standards organizations , including ASTM International 's Committee E-4 on Metallography and some other national and international organizations, have developed standard test methods describing how to characterize microstructures quantitatively. For example,

441-404: A safe, standardized, and ergonomic way by which to hold a sample during the grinding and polishing operations. After mounting, the specimen is wet ground to reveal the surface of the metal. The specimen is successively ground with finer and finer abrasive media. Silicon carbide abrasive paper was the first method of grinding and is still used today. Many metallographers, however, prefer to use

490-440: A slightly different mix; C8–10 Alkane/Cycloalkane/Aromatic Hydrocarbons, Quartz, Kaolin, C12–20 Saturated and Unsaturated Monobasic Fatty Acids, Aqua and Ammonium Hydroxide. Also available are ingredients in a discontinued recipe for Brasso. Wadding: C8–10 Alkane/Cycloalkane/Aromatic Hydrocarbons, Quartz, Ammonium Tallate and Colorant. Liquid: C8–10 Alkane/Cycloalkane/Aromatic Hydrocarbons, Quartz, Kaolin and Ammonium Tallate. Brasso

539-413: A stationary polisher or die grinder , or it may be automated using specialized equipment. When buffing there are two types of buffing motions: the cut motion and the color motion . The cut motion is designed to give a uniform, smooth, semi-bright surface finish. This is achieved by moving the workpiece against the rotation of the buffing wheel, while using medium to hard pressure. The color motion gives

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588-670: A system designed by the Polish physicist Georges Nomarski . This system gives the best detail. DIC converts minor height differences on the plane-of-polish, invisible in BF, into visible detail. The detail in some cases can be quite striking and very useful. If an ST filter is used along with a Wollaston prism , color is introduced. The colors are controlled by the adjustment of the Wollaston prism, and have no specific physical meaning, per se. But, visibility may be better. DIC has largely replaced

637-400: A thin film or varnish that can be peeled off after drying and examined under a microscope. The technique was developed by Pierre Armand Jacquet and others in 1957. Many different microscopy techniques are used in metallographic analysis. Prepared specimens should be examined with the unaided eye after etching to detect any visible areas that have responded to the etchant differently from

686-478: Is a starting point and experienced polishers may vary the materials used to suit different applications. Polishing may be used to enhance and restore the looks of certain metal parts or object on cars and other vehicles, handrails , cookware , kitchenware, and architectural metal. In other applications such as pharmaceutical, dairy, and specialty plumbing, pipes are buffed to help prevent corrosion and to eliminate locations where bacteria or mold may reside. Buffing

735-592: Is abrasive and will wear metal over time. The National Trust recommend alternative cleaners. Brasso has also been used to polish out scratches in plastics: Brasso has been successfully used to take minor (white) heat marks out of French polished wooden surfaces. The fine abrasive cuts through the surface and allows the solvent into the wax and lacquer layer. The surface should be properly cleaned and waxed after this treatment. Brasso has been successfully used to restore Bakelite (telephones, appliances, etc.). Brasso, on account of its ammonia content, has been used as

784-488: Is also used to manufacture light reflectors. Metallography Metallography is the study of the physical structure and components of metals , by using microscopy . Ceramic and polymeric materials may also be prepared using metallographic techniques, hence the terms ceramography , plastography and, collectively, materialography. The surface of a metallographic specimen is prepared by various methods of grinding , polishing , and etching . After preparation, it

833-415: Is becoming more popular because reduced shrinkage during curing results in a better mount with superior edge retention. A typical mounting cycle will compress the specimen and mounting media to 4,000 psi (28 MPa) and heat to a temperature of 350 °F (177 °C). When specimens are very sensitive to temperature, "cold mounts" may be made with a two-part epoxy resin. Mounting a specimen provides

882-471: Is grown epitaxially on the surface to a depth where interference effects are created when examined with BF producing color images, can be improved with PL. If it is difficult to get a good interference film with good coloration, the colors can be improved by examination in PL using a sensitive tint (ST) filter. Another useful imaging mode is differential interference contrast (DIC), which is usually obtained with

931-619: Is known as fine glazing or blue glazing. Sand buffing, when used on German silver , white metal , etc., is technically a buffing operation because it uses a loose abrasive, but removes a significant amount of material, like polishing. White and grey aluminium oxide abrasives are used on high tensile strength metals, such as carbon and alloy steel , tough iron, and nonferrous alloys. Gray silicon carbide abrasives are used on hard and brittle substances, such as grey iron and cemented carbide , and low tensile strength metals, such as brass , aluminium , and copper . Green chromium(III) oxide

980-495: Is of particular concern for copper alloy products such as brass and bronze. While used less extensively than traditional mechanical polishing, electropolishing is an alternative form of polishing that uses the principles of electrochemistry to remove microscopic layers of metal from a base surface. This method of polishing can be fine-tuned to give a wide range of finishes, from matte to mirror-bright. Electropolishing also has an advantage over traditional manual polishing in that

1029-576: Is often analyzed using optical or electron microscopy . Using only metallographic techniques, a skilled technician can identify alloys and predict material properties . Mechanical preparation is the most common preparation method. Successively finer abrasive particles are used to remove material from the sample surface until the desired surface quality is achieved. Many different machines are available for doing this grinding and polishing , which are able to meet different demands for quality, capacity, and reproducibility. A systematic preparation method

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1078-1723: Is the abrasive used in green compounds that are typically used to finish ferrous metals (steels). Polishing wheels come in a wide variety of types to fulfil a wide range of needs. The most common materials used for polishing wheels are wood, leather, canvas, cotton cloth, plastic, felt, paper, sheepskin, impregnated rubber, canvas composition, and wool; leather and canvas are the most common. Wooden wheels have emery or other abrasives glued onto them and are used to polish flat surfaces and maintain good edges. There are many types of cloth wheels. Cloth wheels that are cemented together are very hard and used for rough work, whereas other cloth wheels that are sewn and glued together are not as aggressive. There are cloth wheels that are not glued or cemented, and instead are sewn and have metal side plates for support. Solid felt wheels are popular for fine finishes. Hard roughing wheels can be made by cementing together strawboard paper disks. Softer paper wheels are made from felt paper. Most wheels are run at approximately 7500 surface feet per minute (SFM), however muslin, felt and leather wheels are usually run at 4000 SFM. Buffing wheels, also known as mops, are either made from cotton or wool cloth and come bleached or unbleached. Specific types include: sisal, spiral sewn, loose cotton, canton flannel, domet flannel, denim, treated spiral sewn, cushion, treated vented, untreated vented, string buff, finger buff, sisal rope, mushroom, facer, tampered, scrubbing mushroom, hourglass buff, rag, "B", climax, swansdown, airflow, coolair, and bullet. The following chart will help in deciding which wheels and compounds to use when polishing different materials. This chart

1127-464: Is the easiest way to achieve the true structure. Sample preparation must therefore pursue rules which are suitable for most materials. Different materials with similar properties ( hardness and ductility ) will respond alike and thus require the same consumables during preparation. Metallographic specimens are typically "mounted" using a hot compression thermosetting resin . In the past, phenolic thermosetting resins have been used, but modern epoxy

1176-399: Is the field of taking 0-, 1- or 2-dimensional measurements on the two-dimensional sectioning plane and estimating the amount, size, shape or distribution of the microstructure in three dimensions. These measurements may be made using manual procedures with the aid of templates overlaying the microstructure, or with automated image analyzers. In all cases, adequate sampling must be made to obtain

1225-617: The material safety data sheet for Brasso in North America lists: isopropyl alcohol 3–5%, ammonia 5–10%, silica powder 15–20% and oxalic acid 0–3% as the ingredients. The Australian version also contains silica (silicon dioxide) for abrasives. The online data sheet for Brasso wadding in the UK lists the ingredients as C8–10 Alkane/Cycloalkane/Aromatic Hydrocarbons, Quartz, C14–18 and C16–18 unsaturated Fatty acids, Kaolinite, Aqua, Ammonium Hydroxide and Iron Hydroxide. Brasso liquid lists

1274-411: The LOM but not with EM systems. Also, image contrast of microstructures at relatively low magnifications, e.g., <500X, is far better with the LOM than with the scanning electron microscope (SEM), while transmission electron microscopes (TEM) generally cannot be utilized at magnifications below about 2000 to 3000X. LOM examination is fast and can cover a large area. Thus, the analysis can determine if

1323-505: The amount of a phase or constituent, that is, its volume fraction, is defined in ASTM E 562; manual grain size measurements are described in ASTM E 112 ( equiaxed grain structures with a single size distribution) and E 1182 (specimens with a bi-modal grain size distribution); while ASTM E 1382 describes how any grain size type or condition can be measured using image analysis methods. Characterization of nonmetallic inclusions using standard charts

1372-561: The chemical composition is quantified. But EDS and WDS are difficult to apply to particles less than 2-3 micrometers in diameter. For smaller particles, diffraction techniques can be performed using the TEM for identification and EDS can be performed on small particles if they are extracted from the matrix using replication methods to avoid detection of the matrix along with the precipitate. A number of techniques exist to quantitatively analyze metallographic specimens. These techniques are valuable in

1421-682: The chemical composition of the microstructural features can be determined. The ability to detect low-atomic number elements, such as carbon , oxygen , and nitrogen , depends upon the nature of the detector used. But, quantification of these elements by EDS is difficult and their minimum detectable limits are higher than when a wavelength-dispersive spectrometer (WDS) is used. But quantification of composition by EDS has improved greatly over time. The WDS system has historically had better sensitivity (ability to detect low amounts of an element) and ability to detect low-atomic weight elements, as well as better quantification of compositions, compared to EDS, but it

1470-551: The companies asking for the polish to be recategorized in the hope of reducing costs, but the railways disagreed. As a result of this in 1913 the case was taken to the Railway and Canal Commissioners for a decision. After a hearing lasting two days the commissioners decided in favour of the railway companies, and Brasso remained classed as a dangerous substance for the purposes of railway transport. The polish grew in popularity in Britain, becoming widely available, eventually replacing

1519-418: The crystal structure is non-cubic (e.g., a metal with a hexagonal-closed packed crystal structure, such as Ti or Zr ) the microstructure can be revealed without etching using crossed polarized light (light microscopy). Otherwise, the microstructural constituents of the specimen are revealed by using a suitable chemical or electrolytic etchant. Non-destructive surface analysis techniques can involve applying

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1568-610: The desired finish is achieved. The rough (i.e. large grit) passes remove imperfections within the metal surface like pits, nicks, lines and scratches. The finer abrasives leave progressively finer lines that are not visible to the naked eye. A no. 8 ("mirror") finish requires polishing and buffing compounds, and polishing wheels attached to high speed polishing machines or electric drills . Lubricants like wax and kerosene may be used as lubricating and cooling media during these operations, although some polishing materials are specifically designed to be used "dry." Buffing may be done by hand with

1617-470: The direction elastic parameters of the surface and, as such, it can vividly reveal the surface microstructure of metals. It can also image the crystallographic orientation and determine the single crystal elasticity matrix of the material. If a specimen must be observed at higher magnification, it can be examined with a scanning electron microscope (SEM), or a transmission electron microscope (TEM). When equipped with an energy dispersive spectrometer (EDS),

1666-680: The field of view may be required to observe features such as dendrites . Besides considering the resolution of the optics, one must also maximize visibility by maximizing image contrast . A microscope with excellent resolution may not be able to image a structure, that is there is no visibility, if image contrast is poor. Image contrast depends upon the quality of the optics, coatings on the lenses, and reduction of flare and glare ; but, it also requires proper specimen preparation and good etching techniques. So, obtaining good images requires maximum resolution and image contrast. Most LOM observations are conducted using bright-field (BF) illumination, where

1715-438: The finished product will not experience the compression and deformation traditionally associated with the polishing process. The condition of the material at hand determines what type of abrasive will be applied. The first stage, if the material is unfinished, starts with a rough abrasive (perhaps 60 or 80 grit) and each subsequent stage uses a finer abrasive, such as 120, 180, 220/240, 320, 400 and higher grit abrasives, until

1764-402: The image of any flat feature perpendicular to the incident light path is bright, or appears to be white. But, other illumination methods can be used and, in some cases, may provide superior images with greater detail. Dark-field microscopy (DF), is an alternative method of observation that provides high-contrast images and actually greater resolution than bright-field. In dark-field illumination,

1813-504: The light from features perpendicular to the optical axis is blocked and appears dark while the light from features inclined to the surface, which look dark in BF, appear bright, or "self-luminous" in DF. Grain boundaries , for example, are more vivid in DF than BF. Polarized light (PL) is very useful when studying the structure of metals with non-cubic crystal structures (mainly metals with hexagonal close-packed (hcp) crystal structures). If

1862-415: The metal bottle was replaced by a plastic one. In 2010, Brasso brought out a new product, Brasso Gadgetcare. Gadgetcare is a versatile, non-abrasive gel that can be used on everything from LCD TV screens, laptop screens, computers, smart phones, and PDAs. The plastic bottle is 50ml and is sold with a microfibre cloth. The label of Australian Brasso lists "Liquid Hydrocarbons 630g/L; Ammonia 7g/L", whereas

1911-460: The more expensive, more time-consuming examination techniques using the SEM or the TEM are required and where on the specimen the work should be concentrated. Light microscopes are designed for placement of the specimen's polished surface on the specimen stage either upright or inverted. Each type has advantages and disadvantages. Most LOM work is done at magnifications between 50 and 1000X. However, with

1960-409: The norm as a guide to where microscopical examination should be employed. Light optical microscopy (LOM) examination should always be performed prior to any electron metallographic (EM) technique, as these are more time-consuming to perform and the instruments are much more expensive. Further, certain features can be best observed with the LOM, e.g., the natural color of a constituent can be seen with

2009-413: The older oblique illumination (OI) technique, which was available on reflected light microscopes prior to about 1975. In OI, the vertical illuminator is offset from perpendicular, producing shading effects that reveal height differences. This procedure reduces resolution and yields uneven illumination across the field of view. Nevertheless, OI was useful when people needed to know if a second phase particle

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2058-432: The percentages of various phases present in a specimen if they have different crystal structures. For example, the amount of retained austenite in a hardened steel is best measured using XRD (ASTM E 975). If a particular phase can be chemically extracted from a bulk specimen, it can be identified using XRD based on the crystal structure and lattice dimensions. This work can be complemented by EDS and/or WDS analysis where

2107-544: The previous paste-style polishes. It has undergone very few changes in either composition or package design over the past century. Cans are often collected as a typical example of classic British advertising design. In the US, the current Brasso product is not the same as the legacy product. The manufacturer, Reckitt Benckiser, has not produced the impregnated wadding version of the product for many years. The formula changed in 2008 to comply with US volatile organic compounds law, and

2156-583: The research and production of all metals and alloys and non-metallic or composite materials . Microstructural quantification is performed on a prepared, two-dimensional plane through the three-dimensional part or component. Measurements may involve simple metrology techniques, e.g., the measurement of the thickness of a surface coating, or the apparent diameter of a discrete second-phase particle, (for example, spheroidal graphite in ductile iron ). Measurement may also require application of stereology to assess matrix and second-phase structures. Stereology

2205-424: The specimen is prepared with minimal damage to the surface, the structure can be seen vividly in cross-polarized light (the optic axis of the polarizer and analyzer are 90 degrees to each other, i.e., crossed). In some cases, an hcp metal can be chemically etched and then examined more effectively with PL. Tint etched surfaces, where a thin film (such as a sulfide , molybdate , chromate or elemental selenium film)

2254-416: The specimen, polishing is performed. Typically, a specimen is polished with a slurry of alumina , silica , or diamond on a napless cloth to produce a scratch-free mirror finish, free from smear, drag, or pull-outs and with minimal deformation remaining from the preparation process. After polishing, certain microstructural constituents can be seen with the microscope, e.g., inclusions and nitrides. If

2303-415: The trademark "Brasso" was being sold, initially to railways, hospitals, hotels, and large shops. Because of the hydrocarbon components in the mixture it had a flash point of 72 °F (22 °C) ( Abel Close test ) and so was classed by railway companies as dangerous goods. This classification allowed the railway companies to charge more for distributing Brasso around the country. Reckitt's appealed to

2352-534: Was slower to use. Again, in recent years, the speed required to perform WDS analysis has improved substantially. Historically, EDS was used with the SEM while WDS was used with the electron microprobe analyzer (EMPA). Today, EDS and WDS is used with both the SEM and the EMPA. However, a dedicated EMPA is not as common as an SEM. Characterization of microstructures has also been performed using x-ray diffraction (XRD) techniques for many years. XRD can be used to determine

2401-433: Was standing above or was recessed below the plane-of-polish, and is still available on a few microscopes. OI can be created on any microscope by placing a piece of paper under one corner of the mount so that the plane-of-polish is no longer perpendicular to the optical axis. Spatially resolve acoustic spectroscopy ( SRAS ) is an optical technique that uses optically generated high frequency surface acoustic waves to probe

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