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What is____________? Processes Processes Manufacturing is defined as the mechanical, physical, or chemical transformation of materials or substances into new products. The assembly of components into new products is also considered manufacturing, except when it is appropriately classified as construction. Establishments in the manufacturing sector are often described as plants, factories, or mills and typically use power-driven machines and materials-handling equipment. Also included in the manufacturing sector are some establishments that make products by hand, like custom tailors and the makers of custom draperies. While manufacturers typically do not sell to the public, some establishments like bakeries and candy stores that make products on the premises may be included. Definition from the U.S. Census Bureau Activities involved in
mechanical engineering, include:
Careers
in Engineering: In engineering, any process in which two or more pieces of metal are joined together by the application of heat, pressure, or a combination of both. Most of the processes may be grouped into two main categories: pressure welding, in which the weld is achieved by pressure; and heat welding, in which the weld is achieved by heat. Heat welding is the most common welding process used today. Brazing and soldering are other means of joining metals. Along with soldering and brazing, it is essential in the production of virtually every manufactured product involving metals. The use of electron beams and lasers for welding has grown during the second half of the 20th century. These methods produce high-quality welded products at a rapid rate. Laser welding and electron-beam welding have valuable applications in the automotive and aerospace industries. Careers in Welding: A field of engineering and
applied physics dealing with the design and application of devices,
usually electronic circuits, the operation of which depends on the flow of
electrons for the generation, transmission, reception, and storage of
information. Careers in Electronics: A machine tool is a power-operated tool used for finishing or shaping metal parts, especially parts of other machines. Machine tools operate by removing material from the workpiece. Basic machining operations are: (1) turning, the shaping of a piece having a cylindrical or conical external contour; (2) facing, the shaping of a flat circular surface; (3) milling, the shaping of a flat or contoured surface; (4) drilling, the formation of a cylindrical hole in a workpiece; (5) boring, the finishing of an existing cylindrical hole, as one formed by drilling; (6) broaching, the production of a desired contour in a surface; (7) threading, the cutting of an external screw thread; and (8) tapping, the cutting of an internal screw thread. The materials used in machine tools must be extremely hard and durable. Thus, their working surfaces are made of such substances as high-speed steels, sintered carbides, and diamonds. To help dissipate the heat, the area of contact between the working surface and the workpiece is usually lubricated with a fluid that may also improve the finish of the workpiece's surface. Modern machine tools are often numerically or computer controlled. Careers in
Machining: A branch of engineering concerned mainly with moving liquids. The term is applied commonly to the study of the mechanical properties of water, other liquids, and even gases when the effects of compressibility are small. Hydraulics can be divided into two areas, hydrostatics and hydrokinetics. Hydrostatics, the consideration of liquids at rest, involves problems of buoyancy and flotation, pressure on dams and submerged devices, and hydraulic presses. The relative incompressibility of liquids is one of its basic principles. Hydrodynamics, the study of liquids in motion, is concerned with such matters as friction and turbulence generated in pipes by flowing liquids, the flow of water over weirs and through nozzles, and the use of hydraulic pressure in machinery. Careers in
Manufacturing: Metallurgy is a science of extracting metals from their ores by smelting (metal is treated by fire, chemicals or electrical process), refining, etc. Modern metallurgical research is concerned with the preparation of radioactive metals, with obtaining metals economically from low-grade ores, with obtaining and refining rare metals hitherto not used, and with the formulation of alloys. Metallurgy is the art, science and technology of making metals and alloys into forms suitable for practical use. Some metals are found in their "native" or free elemental form (example gold, silver, copper), and a limited number can be produced from seawater, notably magnesium. Process metallurgy is concerned with the extraction of metals from their ores and with the refining of metals. Physical metallurgy is about the physical and mechanical properties of metals as affected by composition, processing, and environmental conditions. Mechanical metallurgy deals with the response of metals to applied forces. Manufacturing Machines Computer Numerical Control machining is a form of machining in which a computer processor is linked to a machine tool. It is a system in which programmed numerical values are directly inserted and stored on some form of input medium, and automatically read and decoded to cause a corresponding movement in the machine which it is controlling. Since its inception in 1953 CNC has continued to play an increasingly important role in product manufacturing. With the tools and machines that are available, manufacturing facilities now have the capability of reproducing parts at an exceptional rate with repeatable accuracy. Technology in manufacturing methods us changing rapidly. Today 90% of all machine tools manufacturing in the world are computerized to enhance capability. Students must have the basics of CNC to have a chance to compete in the skilled trades workforce of today. It becomes even more important for tomorrow's workforce. Careers in Manufacturing: A machine tool for holding and turning metal, wood, plastic, or other material against a cutting tool to form a cylindrical product or part. It also drills, bores, polishes, grinds, makes threads, and performs other operations. Its principal parts are the headstock (attached to the bed or base of the machine), which holds one end of the material in a rotating spur; the tailstock, which holds the other end, moves along the bed, and can be clamped in position at any point; the cutting tool; and the power feed, comprising the drive and its motive parts. The major function of the engine lathe is to change the size, shape, or finish of a revolving workpiece by one cuts or a series of cuts into the workpiece with cutting tools that can be adjusted to the workpiece. With proper attachments and adjustments, a lathe can also drill, bore, ream, tape, and thread. The variety of operations the engine lathe can perform make it one of the most useful and necessary machines in the shop.
Careers in Manufacturing: The drill press is one of the most frequently used machine tools. Its principle purpose is the cutting of round holes into or through materials. This machine employs a variety of cutting tools; the twist drill is most common. Drilled holes may be finished or modified by reaming, boring, countersinking, counter-boring, spot-facing, and tapping. Surface grinding is done to produce flat surfaces on workpieces held in contact with a grinding wheel. Other types of precision grinders are available to grind other shapes or contours. The grinding operation depends upon the abrasive or cutting qualities of emery, corundum, carborundum, or other materials bonded and formed into a wheel. The grinding wheel and the grinding machines have become such important factors today that without them our mass production would be impossible. Because of the construction and accuracy of grinding machines today, workpieces can be held to extremely close tolerances in dimension and finish. Milling is the process of producing machined surfaces by progressively removing a predetermined amount of material from the workpiece, which is fed to a rotating milling cutter. One of the characteristic features of the milling process is that each milling cutter tooth removed its share of stock in the form of individual chips. The quality of finish, or the physical character of a machined surface produced by the milling process is determined by the method of milling. There are two basic methods of milling - peripheral milling and face milling. Careers in Manufacturing: Modern robotics has produced innumerable devices that replace human personnel and the term robot is used to designate much of this machinery. Most robotic systems are anchored to fixed positions in factories where they perform a flexible, but restricted, number of operations in computer-aided manufacturing. Such a system minimally contains a computer to control operations and effecters, devices that perform the desired work. Additionally, it might have sensors and auxiliary equipment or tools under its control. Other more complex, multitask systems use sensory systems to gather information needed to control its work. A robot's sensors might provide tactile feedback, so that it can pick up objects and place them properly, without damaging them. Another robot sensory system might include a form of machine vision that can detect flaws in manufactured goods. Some robots used to assemble electronic circuit boards can place odd-sized components in the proper location after visually locating positioning marks on the board. Computer-aided design or CAD is a form of automation that helps designers prepare drawings, specifications, parts lists, and other design-related elements using special graphics- and calculations-intensive computer programs. The technology is used for a wide variety of products in such fields as architecture, electronics, and aerospace, naval, and automotive engineering. They include three-dimensional modeling and computer-simulated operation of the model. Rather than having to build prototypes and change components to determine the effects of tolerance ranges, engineers can use computers to simulate operation to determine loads and stresses. Among the benefits of such systems are lower product-development costs and a greatly shortened design cycle. State-of-the-art CAD systems running on workstations and mainframe computers are increasingly integrated with computer-aided manufacturing (CAM) systems, a form of automation where computers communicate work instructions directly to the manufacturing machinery. Today a single computer can control banks of robotic milling machines, lathes, welding machines, and other tools, moving the product from machine to machine as each step in the manufacturing process is completed.
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