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Tumble Finishing
Tumble finishing, also known as tumbling or rumbling, is a technique for smoothing and polishing a rough surface on relatively small parts. In the field of metalworking, a similar process called barreling, or barrel finishing,Degarmo, p. 781. works upon the same principles. Tumbled stones are made with rock tumblers in a process very similar to the natural processes that produce "sea glass" or "beach glass". Stones Tumbling of rocks as a lapidary technique for rock polishing usually requires a plastic or rubber-lined barrel loaded with a consignment of rocks, all of similar or the same hardness, some abrasive grit, and a liquid lubricant. Silicon carbide grit is commonly used, and water is a universal lubricant. The barrel is then placed upon slowly rotating rails so that it rotates. The optimal speed of rotation depends on the size of the tumbler barrel and materials involved. Vibratory finishing process can be used instead. A well-chosen speed for stone polishing causes t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bridal Crown With Rock Crystals 3
A bride is a woman who is about to be married or who is a newlywed. When marrying, if the bride's future spouse is a man, he is usually referred to as the ''bridegroom'' or just ''groom''. In Western culture, a bride may be attended by a maid, bridesman and one or more bridesmaids. The word "bride" has its roots in the Old English word ''bryd'', which is shared with other Germanic languages. In Western countries, brides typically wear white wedding dresses, a tradition started by Queen Victoria. The white dress was once considered a symbol of luxury due to the difficulties in laundering delicate white clothing. Today, Western brides may wear white, cream, or ivory dresses, regardless of their number of marriages. In non-Western countries, brides often wear national dress, with white wedding dresses being uncommon in Asian cultures as it symbolizes mourning and death. Red, on the other hand, represents vibrancy and health and is commonly worn by brides in many Asian cultures. Br ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Industrial Processes
Industrial processes are procedures involving chemical, physical, electrical, or mechanical steps to aid in the manufacturing of an item or items, usually carried out on a very large scale. Industrial processes are the key components of heavy industry. Chemical processes by main basic material Certain chemical process yield important basic materials for society, e.g., (cement, steel, aluminum, and fertilizer). However, these chemical reactions contribute to climate change by emitting carbon dioxide, a greenhouse gas, through chemical reactions, as well as through the combustion of fossil fuels to generate the high temperatures needed to reach the activation energies of the chemical reactions. Cement (the paste within concrete) * Calcination – Limestone, which is largely composed of fossilized calcium carbonate (CaCO3), breaks down at high temperatures into useable calcium oxide (CaO) and carbon dioxide gas (), which gets released as a by-product. This chemical reaction, c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Handicrafts
A handicraft is a traditional main sector of craft making and applies to a wide range of creative and design activities that are related to making things with one's hands and skill, including work with textiles, moldable and rigid materials, paper, plant fibers, clay, etc. One of the oldest handicraft is Dhokra; this is a sort of metal casting that has been used in India for over 5,000 years and is still used. In Sistan and Baluchestan Province, Iranian Baluchistan, women still make red ware hand-made pottery with dotted ornaments, much similar to the 4,000-year-old pottery tradition of Kalpurgan, an archaeological site near the village. Usually, the term is applied to traditional techniques of creating items (whether for personal use or as products) that are both practical and aesthetic. Handicraft industries are those that produce things with hands to meet the needs of the people in their locality without using machines. Collective terms for handicrafts include artisanry, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ball Mill
A ball mill is a type of grinder filled with grinding balls, used to grind or blend materials for use in mineral dressing processes, paints, pyrotechnics, ceramics, and selective laser sintering. It works on the principle of impact and attrition: size reduction is done by impact as the balls drop from near the top of the shell. A ball mill consists of a hollow cylindrical shell rotating about its axis. The axis of the shell may be either horizontal or at a small angle to the horizontal. It is partially filled with balls. The grinding media are the balls, which may be made of steel ( chrome steel), stainless steel, ceramic, or rubber. The inner surface of the cylindrical shell is usually lined with an abrasion-resistant material such as manganese steel or rubber lining. Less wear takes place in rubber lined mills. The length of the mill is approximately equal to its diameter. The general idea behind the ball mill is an ancient one, but it was not until the Industrial Revo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
3D Printing
3D printing, or additive manufacturing, is the construction of a three-dimensional object from a CAD model or a digital 3D model. It can be done in a variety of processes in which material is deposited, joined or solidified under computer control, with the material being added together (such as plastics, liquids or powder grains being fused), typically layer by layer. In the 1980s, 3D printing techniques were considered suitable only for the production of functional or aesthetic prototypes, and a more appropriate term for it at the time was rapid prototyping. , the precision, repeatability, and material range of 3D printing have increased to the point that some 3D printing processes are considered viable as an industrial-production technology; in this context, the term ''additive manufacturing'' can be used synonymously with ''3D printing''. One of the key advantages of 3D printing is the ability to produce very complex shapes or geometries that would be otherwise infeasi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dice
A die (: dice, sometimes also used as ) is a small, throwable object with marked sides that can rest in multiple positions. Dice are used for generating random values, commonly as part of tabletop games, including dice games, board games, role-playing games, and games of chance. A traditional die is a cube with each of its six faces marked with a different number of dots ( pips) from one to six. When thrown or rolled, the die comes to rest showing a random integer from one to six on its upper surface, with each value being equally likely. Dice may also have other polyhedral or irregular shapes, may have faces marked with numerals or symbols instead of pips and may have their numbers carved out from the material of the dice instead of marked on it. Loaded dice are specifically designed or modified to favor some results over others, for cheating or entertainment purposes. History Dice have been used since before recorded history, and their origin is uncertain. It is hypoth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mosaic
A mosaic () is a pattern or image made of small regular or irregular pieces of colored stone, glass or ceramic, held in place by plaster/Mortar (masonry), mortar, and covering a surface. Mosaics are often used as floor and wall decoration, and were particularly popular in the Ancient Rome, Ancient Roman world. Mosaic today includes not just murals and pavements, but also artwork, hobby crafts, and industrial and construction forms. Mosaics have a long history, starting in Mesopotamia in the 3rd millennium BC. Pebble mosaics were made in Tiryns in Mycenean civilisation, Mycenean Greece; mosaics with patterns and pictures became widespread in classical times, both in Ancient Greece and Ancient Rome. Early Christian basilicas from the 4th century onwards were decorated with wall and ceiling mosaics. Mosaic art flourished in the Byzantine Empire from the 6th to the 15th centuries; that tradition was adopted by the Norman dynasty, Norman Kingdom of Sicily in the 12th century, by th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Slag
The general term slag may be a by-product or co-product of smelting (pyrometallurgical) ores and recycled metals depending on the type of material being produced. Slag is mainly a mixture of metal oxides and silicon dioxide. Broadly, it can be classified as ferrous (co-products of processing iron and steel), ferroalloy (a by-product of ferroalloy production) or non-ferrous/ base metals (by-products of recovering non-ferrous materials like copper, nickel, zinc and phosphorus). Within these general categories, slags can be further categorized by their precursor and processing conditions (e.g., blast furnace slags, air-cooled blast furnace slag, granulated blast furnace slag, basic oxygen furnace slag, and electric arc furnace slag). Slag generated from the EAF process can contain toxic metals, which can be hazardous to human and environmental health. Due to the large demand for ferrous, ferralloy, and non-ferrous materials, slag production has increased throughout the years des ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Surface Harden
Case-hardening or carburization is the process of introducing carbon to the surface of a low-carbon iron, or more commonly a low-carbon steel object, in order to harden the surface. Iron which has a carbon content greater than ~0.02% is known as steel. Steel which has a carbon content greater than ~0.25% can be direct-hardened by heating to around 600°C, and then quickly cooling, often by immersing in water or oil, known as quenching. Hardening is desirable for metal components because it gives increased strength and wear resistance, the tradeoff being that hardened steel is generally more brittle and less malleable than when it is in a softer state. In order to produce a hard skin on steels which have less than ~0.2% carbon, carbon can be introduced into the surface by heating steel in the presence of some carbon-rich substance such as powdered charcoal or hydrocarbon gas. This causes carbon to diffuse into the surface of the steel. The depth of this high carbon layer depends ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Burnishing (metal)
Burnishing is the deformation (engineering), plastic deformation of a surface due to friction, sliding contact with another object. It smooths the surface and makes it shinier. Burnishing may occur on any sliding surface if the contact stress locally exceeds the yield (engineering), yield strength of the material. The phenomenon can occur both unintentionally as a failure mode, and intentionally as part of a metalworking or manufacturing process. It is a squeezing operation under cold working. Failure mode (unintentionally) The action of a hardened ball against a softer, flat plate illustrates the process of burnishing. If the ball is pushed directly into the plate, stresses develop in both objects around the area where they contact. As this normal force increases, both the ball and the plate's surfaces deform. The deformation caused by the hardened ball increases with the magnitude of the force pressing against it. If the force on it is small, when the force is released both ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Making A Silver Chain, 23 (25)
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