Term
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Definition
| attractive means of joining the various layers and can be applied to both metallic and nonmetallic materials. The lamination of polymer matrix composites often utilizes films of unpolymerized resin that are introduced between the layers. Pressing at elevated temperature then cures the resin and completes the load |
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Term
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Definition
| in dealing with tempered glass, this can be used to reduce unfavorable residual stresses that might lead to cracking |
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Term
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Definition
| Higher heats and pressures can be used when the part is cured in this, which limits the size of the product. The supporting molds and vacuum-bagged layups are placed inside a heated pressure vessel where curing occurs under elevated temperatures and pressures in the range 0.4 to 0.7 MPa (50 to 100 psi). |
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Term
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Definition
| a variety of ____ processes have been developed, the most common being used to convert thermoplastic polythene chloride (PVC), polypropylene, and PEEK resins into bottles and other hollow-shape containers. Variations of ____ have been designed to provide both axial and radial expansion of the plastic (for enhanced strength) as well as to produce multilayered products |
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Term
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Definition
| To overcome failures in laminar-type composites such as interlaminar cracking and delamination upon impact, high strength reinforcing fibers can also be interwoven into 3D performs by processes that include weaving, stitching and ____ though the thickness of stacked 2D performs |
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Term
| Bulk-Molding Compound (475 |
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Definition
| - A modification of compression molding that is used when quantities are large and quality needs to be high, a ____, or a preformed mat, is placed on the press, and heat and pressure are applied. With heated dies, the thermoset curing occurs during the compression operation, and cycles range from 1 to 5 minutes at temperatures ranging from 110 to 160 Fahrenheit and 1 to 7 MPa. |
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Term
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Definition
| In the ____ process, a mass of dough-like thermoplastic is forced between and over two or more counterrotating rolls to produce thin sheets or films of polymer, which are then cooled to induce hardening |
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Term
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Definition
| This is the simplest of the shape forming processes because no fillers are used and no pressure is required. While not all plastics can be ____, there are a number of capable thermoplastics, including acrylics, urethanes, and PVC plastisols. The thermoplastic polymer is simply melted and the liquid is poured into a container having the shape of the desired part |
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Term
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Definition
| This is an alternative method of producing strength that does not require elevated temperature. A liquid binder material is used to coat the ceramic particles, and a subsequent chemical reaction converts the liquid to a solid, forming strong, rigid bonds |
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Term
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Definition
| The fabrication processes applied to ____ materials generally fall into 2 distinct classes, based on the properties of the material: glasses if the material can be shaped by means of viscous flow, or crystalline ____ if the material is hard and brittle, with high melting points |
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Term
| Ceramic-matrix Composites (477) |
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Definition
| Unlike polymeric or metal-matrix composites, where failures originate in or along the reinforcement fibers, _____ often fail due to flaws in the matrix. If the reinforcement is bonded strongly to the matrix, a matrix crack will propagate right through to the fibers. |
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Term
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Definition
| These are based on special types of ceramics blended with water and various additives to produce a material that can be shaped by most of the traditional forming methods |
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Term
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Definition
| this, the uncured thermosetting material is pressed to shape while cold and is then removed from the mold and cured in a separate oven. |
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Term
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Definition
| engineered materials made from two or more constituent materials with significantly different physical or chemical properties which remain separate and distinct on a macroscopic level within the finished structure |
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Term
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Definition
| When production quantities are large and quality needs to be high, matched metal dies can be substituted for the mold and bag, the process then becomes a modification of this. In this, a sheet-molding compound, bulk-molding compound, or a preformed mat is placed on the press, and heat and pressure are applied. |
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Term
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Definition
| have a characteristically brittle behavior and are normally manufactured into useful components; hard, brittle materials with high melting points, that cannot be formed by techniques requiring either plasticity or melting. Instead, these materials are generally processed in the solid state by techniques that utilize particles or aggregates and resemble those used in powder metallurgy. |
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Term
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Definition
| a special heat treatment that controls the nucleation and growth of the crystalline component, used to fabricate glass ceramics. |
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Term
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Definition
| process used to produce relatively thin parts with uniform wall thickness, such as boots, gloves, and fairings. The simplest fabrication process for rubbers and elastomers. |
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Term
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Definition
| used in the fabrication of crystalline ceramics, this is a common technique that enables dry powders to be pressed into useful shapes |
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Term
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Definition
| A material that behaves like rubber but is made from synthetic polymers and is superior to rubber in several mechanical or chemical properties. |
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Term
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Definition
| his is another practical means of bonding layers of metals. In this a piece of explosive material progressively detonates above layers to be be joined, causing a pressure wave to sweep across the interface |
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Term
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Definition
| Products such as inner tubes, graden hoses, tubing and strip moldings (long plastic products with uniform cross sections) can be produced by this, where a compounded material is forced through a die by a screw device similar to that described for plastics. |
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Term
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Definition
| used to reinforce composites; these are embedded in a selected matrix with the proper alignment and spacing to produce the desired properties. Can be continuous or discontinuous. |
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Term
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Definition
| s a fabrication technique for creating composite material structures. The process involves winding filaments under varying amounts of tension over a male mould or mandrel. The mandrel rotates while a carriage moves horizontally, laying down fibers in the desired pattern. |
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Term
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Definition
| his is a subsequent heating process; slurry –type materials must first be dried in a controlled manner that is designed to control dimensional changes and minimize stresses. The material is then heated to temperatures between .5 to .8 times the absolute melting point. AKA sintering |
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Term
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Definition
| in this, a foaming agent is mixed with the plastic resin and releases gas or volatilizes when the material is heated during molding |
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Term
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Definition
| one of two distinct classes of ceramic materials when applied to the fabrication process of ceramic materials. Glass can be manufactured into useful articles by first heating the material to produce a molten or viscous state, shaping the material by means of viscous flow, and then cooling the material to produce a solid product. Typically brittle, and optically transparent. |
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Term
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Definition
| form a unique class of materials that are part crystalline and part glass. They are fabricated into shape as a glass, and are then subjected to a special heat treatment (devitrification) that controls the nucleation and growth of the crystalline component. Final properties include good strength and toughness, along with low thermal expansion. Typical products include cookware, and materials used in electrical and computer components. |
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Term
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Definition
| when the quality demands are not as great and the reinforcement-to-resin ratio is not exceptionally high, pressing operations can often be eliminated. The layers of pliable resin-coated cloth are simple placed in an open mold or draped over a form in a process known as hand layup or open mold processing. Squeegees or rollers are used to manually ensure good contact and remove any entrapped air, and the assembly is then allowed to cure, generally at room temperature. The hand layup process is slow and labor intensive and has part to part and operator to operator variability. |
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Term
| Hot-isostatic Pressing 467 |
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Definition
| common technique in fabricating crystalline ceramics because crystalline ceramics cannot be formed by techniques requiring either plasticity or melting. Exhibit features and limitations similar to those discussed in ch 16. |
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Term
| Injection Molding 466 - I |
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Definition
| Injection molding of fiber-reinforced plastics is a process that competes with metal die castings and offers comparable properties at considerably reduced weight. In the simplest variation, chopped or continuous fibers are placed in a mold cavity that is then closed and injected with resin. |
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Term
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Definition
| metal, often incorporated into plastic products to provide enhanced performance or unique features. Can be used to provide threaded cavities, holes, and alignment pins in plastic parts. |
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Term
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Definition
| used in fabricating crystalline ceramics. Exhibits features and limitations similar to those discussed in ch 16. |
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Term
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Definition
| in the ____ process, prepregs(a fibrous material preimpregnated with a synthetic resin), mats, or tapes are stacked to produce a desired thickness and cured under pressure and heat. Resulting products possess unusually high strength properties as a result of the integral fiber reinforcement. |
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Term
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Definition
| (laser molting) Prototypes or small production quantities of ceramic products have also been made by the laser sintering of ceramic powders. Parts are made by building up successive layers of material by laser sintering of thin layers of heat-fusible powder. For ceramic parts, the polymer coating on the powder is bonded by the laser. |
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Term
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Definition
| stacked to produce a desired thickness and cured under pressure and heat in the lamination process. |
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Term
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Definition
| is composite material with at least two constituent parts, one being a metal. The other material may be a different metal or another material, such as a ceramic or organic compound. When at least three materials are present, it is called a hybrid composite. An MMC is complementary to a cermet. |
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Term
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Definition
| Where the layers of liable resin-coated cloth are simply placed in an open mold or draped over a form. |
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Term
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Definition
| A round, solid-bottom, hollow-tube preform. It is made from heated plastic by either extrusion or injection molding. |
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Term
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Definition
| Is shown to be substantially different from metals in both structure and properties. Tends to be used closer to their design limits, and many fabrication processes convert the raw plastic into a finished product on a single operation. |
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Term
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Definition
| Involves the formation of a woven fabric that has been infiltrated with a matrix material. |
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Term
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Definition
| A flexible membrane is positioned over the female mold cavity and pressurized to force the individual plies together and drive out entrapped air and excess resin. |
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Term
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Definition
| A continuous process that is used to produce relatively simple shapes of uniform cross section, such as round, rectangular, tubular, plate, sheet, and structural products. |
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Term
| Reaction injection molding 455 459 - P |
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Definition
| Process, in which two or more liquid monomers are metered into a unit where they are intimately mixed by the impingement of liquid streams that have been pressurized to a value between 13 and 20 MPa (2000 and 3000 psi). |
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Term
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Definition
| In ___ the resin is injected or drawn into a mold, which contains the fibres, from a homogeniser under low pressure. |
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Term
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Definition
| A means of producing fiber-reinforce metal products. Clad metals are joined by a roll bonding and thermal treatment process that produces a metallurgical bond as the lattice structures of the metals are forced into conformance with each other. High pressure, producing massive deformation of the metals, causes a sharing of electrons at the interface, which produces a bond on the atomic level. No intermediate layers such as adhesives or braze metal are involved. |
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Term
| Rotational molding 455 460 - |
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Definition
| can be used to produce hollow, seamless products of a wise variety of sizes and shapes, including storage tanks, bins and refuse containers, doll parts, footballs, helmets, and even boat hulls. The process begins with a closed mold or cavity that has been filled with a premeasured amount of thermoplastic powder or liquid. The molds are either preheated or placed in a heated oven and are then rotated simultaneously about two perpendicular axes. |
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Term
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Definition
| (couldn't find in the book - from dictionary) a slightly twisted roll or strand of usually textile fibers |
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Term
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Definition
| - In ____ such as corrugated cardboard or the honeycomb shown in Figure 20-19, thin layers of facing material are bonded, usually by adhesive to a lightweight filler material. |
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Term
| Sheet-molding compound 457 475 - |
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Definition
| Bulk compound molding compound, or preformed mat is placed on the press, and heat and pressure are applied. Temps usually range from 110-160 F and pressures from 1-7 MPa. With heated dies, the thermoset curing occurs during the compression operation, and cycles range from 1 to 5 minutes. |
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Term
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Definition
| The processes described previously can all be used to produce useful shapes from ceremic materials, but useful strength generally requires a subsequent hearing operation known as firing or ____. |
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Term
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Definition
| In this process, ceramic powder is mixed with a liquid to form a slurry, which is then cast into a mold containing very fine pores. Capillary action pulls the liquid from the slurry, allowing the ceramic particles to arrange into a "green" body with sufficient strength for subsequent handling. Hollow shapes can be produced by pouring out the remaining slurry once a desired thickness of solid has formed on the mold walls. |
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Term
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Definition
| Filaments, fibers, and yarns can be produced by spinning, a modified form of extrusion. Molten thermoplastic polymer is forced through a die containing many small holes. Where multi-strand yarns or cables are desired, the dies can rotate or spin to produce the twists and wraps. |
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Term
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Definition
| When continuous or woven fibers are not required to produce the desired properties, sheet-type parts can be produced by mixing chopped fibers and catalyzed resin and spraying the combination into or onto a mold form, as shone in Figure 20-25. Rollers or squeegees can be used to remove entrapped air and work the resin into the reinforcement. Room-temperature curing is usually preferred, but elevated temperatures are sometimes used to accelerate the cure. As with the hand layup process, an initial gel coat can be used to produce a smooth, pigmented surface. |
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Term
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Definition
| In the lamination process, prepregs, mats or _____ are stacked to produce a desired thickness and cured under pressure and heat |
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Term
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Definition
| Glass created through special heat treatments. Applying forced cooling to the exposed surfaces, a residual stress pattern of surface compression can be induced creating tempered glass. This glass is stronger and more fracture resistant, since cracks tend to initiate on free surfaces. |
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Term
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Definition
| In the _____ process, thermoplastic sheet material is heated to a working temperature and then formed into a finished shape by heat, pressure, or vacuum. |
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Term
| Thermoplastic polymer 455 - |
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Definition
| These can be heated to produce either a soft, formable solid or a liquid. The polymerized material can then be cast, injected into a mold, or forced into or through dies to produce a desired shape. |
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Term
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Definition
| Untwisted assemblies of fibers. |
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Term
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Definition
| Is sometimes used to reduce the turbulence and uneven flow that can result from the high pressures of hot-compression molding. Transfer molding combines elements of both compression molding and injection molding and enables some of the advantages of injection molding to be utilized with thermosetting polymers. |
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Term
| Vacuum-bag molding 474 - I |
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Definition
| In this process, air pressure holds the laminate against the mold while the resin cures (curing generally occurs at room temperature). |
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Term
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Definition
| Process of shaping material at a molten state (glass in this case). |
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Term
| Vitrification (internet) - |
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Definition
| The transition of a substance into glass. |
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Term
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Definition
| Twisted assemblies of filaments. |
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Term
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Definition
| Ceramics are made of pure aluminum oxide. Used as a metallic binder. |
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Term
| BUE (built up edge) (512, 528) |
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Definition
| A variation of the continuous chip, often encountered in machining ductile materials, and is associated with a built up edge formation on the cutting tool. The local high temp. and extreme pressure in the cutting zone caused the work material to adhere or pressure weld to the cutting edge of the tool forming the built up edge rather like a dead metal zone in the the extrusion process. Although this material protects the cutting edge from wear it modifies the geometry of the tool. BUE's are not stable and will break off periodically adhering to the chip or passing under the tool and remaining on the machine surface. BUE formation can be eliminated or minimized by reducing the depth of cut, altering the cutting speed, using positive rake tools, applying a coolant, or changing cutting tool materials. |
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Term
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Definition
| Carbides, which are non-ferrous alloys, are also called sintered (or cemented) carbides because they are manufactured by powder metallurgy techniques. |
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Term
| Cast Cobalt Alloy(515, 523) |
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Definition
| Popularly known as steelite tools. Are cobalt rich, chromium tungsten carbon cast alloys having properties and applications in the intermediate range between high-speed steel and cemented carbides. Retain their hardness to a much higher temperature than high-speed steel tools. Are hard as cast, and can not be softened or heat treated. The casting provides a tough core and elongated grains normal to the surface. The structure is not however homogeneous. The tools made of cast cobalt alloys are generally cast to shape and finished size by grinding. They are only available in simple shapes such as single point tools, and saw blades because of limitations in the casting process and expense involved in the final shaping (grinding). Materials machinable with this tool material include plain carbon steels, alloy steels, non-ferrous alloys, and cast iron. |
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Term
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Definition
| Made of pure aluminum oxide, ceramics are usually in the form of disposable tips. Can be operated at 2 to 3 times the cutting speed of tungsten carbide. Almost completely resist cratering. Run with no coolant, and have about the same tool life at their higher speeds as tungsten carbide does at lower speeds. Ceramics are usually as hard as carbides but are more brittle and therefore require more rigid tool holders and machine tools in order to take advantage of their capabilities. Ceramics are a good material for high speed finishing and/or high removal rate machining applications of super alloys, hard chill cast iron and high strength steels. Edge chipping usually the dominate mode of tool failure. |
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Term
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Definition
| A new class of tool materials best suited for finishing. Cermets have superior wear resistance, longer tool life, and can operate at higher cutting speeds. They have higher hot hardness and oxidation resistance than cemented carbides. The better finish imparted by a cermet is due to its low level of chemical reaction with iron(less cratering and BUE). Cermets are usually cold pressed and proper processing techniques are required to prevent insert cracking. |
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Term
| Chemical Vapor Deposition(CVD)(520) |
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Definition
| One of the most effective coating processes for improving the life and performance of tools. Used to deposit a protective coating onto carbide inserts and has been benefiting the metal removal industry for many years, and is now being applied with equal success to steel. CVD is an atmosphere controlled process carried out at temperatures in the range of 950 to 1050 degrees Celsius. 85% of carbide tools are coated almost exclusively by CVD. This allows for quicker cutting speed. |
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Term
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Definition
| Coated tools only cost 15-20% more than uncoated tools, so a modest improvement in performance can justify the added cost. 15-20% of all tool steels are coated, mostly by the PVD process. |
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Term
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Definition
| wear on the rake face of the tool Think of wearing on the threads of a screw. |
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Term
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Definition
| directly influence the productive of the machining operation ie. the hardness of the material to be cut, the speed of the cut...... |
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Term
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Definition
| is the depth the tool must travel trough the material this will effect the life of the tool and the time it takes to complete the task |
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Term
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Definition
| The hard material known. Man made diamonds are used as tools in machining very hard metals |
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Term
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Definition
| the ability of a steel to withstand high temperatures with out loosing its hardens. This is very attractive in tools that cut extremely hard materials |
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Term
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Definition
| refers to the ease with which a metal can be machined to an acceptable surface finish. The principal definitions are based on material properties, tool life, and cutting speed. |
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Term
| Physical vapor deposition (PVD)(520) |
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Definition
| an effective coating process for improving the life and performance of tools, used on about 15-20% of all tool steels. The three methods (preformed under a hard vacuum) in use are reactive sputtering, reactive ion plating, and arc evaporation. |
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Term
| Polycrystalline diamond tools(530) |
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Definition
| consists of a thin layer of diamond particles sintered together and metallurgically bonded to a cemented carbide substrate. |
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Term
| Single-crystal diamonds(530) |
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Definition
| used for precision machining of large mirrors. Also used to machine brass watch faces, and slice biological materials to view under microscopes. |
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Term
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Definition
| also called cemented are carbides because they are manufactured by powder metallurgy techniques. |
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Term
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Definition
| (523) also called cast cobalt alloys are cobalt rich, chromium-tungsten-carbon cast alloys and retain their hardness at high temperatures, so they can be used at higher cutting speeds. |
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Term
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Definition
| the coating used in PVD and is formed by reacting free titanium ions with nitrogen away from the surface of the tool and using physical means to transport the coating |
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Term
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Definition
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Term
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Definition
| The angle that the tool makes with respect to a vertical from the workpiece. |
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Term
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Definition
| process of enlarging a hole that has already been drilled. |
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Term
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Definition
| In this the cutting tool moves into the work while the work remains stationary. |
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Term
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Definition
| A self-excited vibration that is caused by the closed-loop force-displacement response of the machining process. |
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Term
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Definition
| a formation on the cutting tool, is associated with a variation of the continuous chip, often encountered in machining ductile materials. |
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Term
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Definition
| can be determined dynamically if a reliable means to measure Vc can be found. |
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Term
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Definition
| the velocity of the chip being sheared. |
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Term
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Definition
| This is a material property related to shear flow stress, hardness and work hardening and is often described in a relative sense of the machinability of materials. |
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Term
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Definition
| are mounted in machine tools, which provide the required movement of the tool with respect to the work (or vice versa) to accomplish the process desired. |
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Term
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Definition
| _________ is the distance the tool has plunged into the surface. ______=(D1-D2)/2 D1:initial diameter, D2:final diameter |
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Term
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Definition
| is a cutting process that uses a bit to cut or enlarge a hole in solid materials. It cuts by applying pressure and rotation to the workpiece, which forms chips at the cutting edge. |
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Term
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Definition
| amount of material removed per revolution or per pass of the tool over the workpiece |
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Term
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Definition
| Force resisting the relative movement. Gets stronger with increased surface area, and/or pressure. |
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Term
| Grinding (Abrasive Machining) |
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Definition
| Using a rough(abrasive) grinding wheel to cut away at metal. Usually only useful for shallow cuts and finishing. |
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Term
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Definition
| powered mechanical device used to fabricate metal components of by selective removal of metal. |
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Term
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Definition
| _________ moves the workpiece radially against the rotating cutter, which cuts on its sides as well as its tip. |
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Term
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Definition
| In _______ machining, the cutting edge and cutting motion are not perpendicular to each other. |
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Term
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Definition
| done to test machining mechanics and theory. Is the measurement of two forces and can be obtained in laboratory practice by: machining a plate, end cutting a tube wall in a turning setup, and end cutting a plate feeding in a facing direction. |
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Term
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Definition
| one of the seven basic chip formation processes. |
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Term
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Definition
| the periodic response of the system to a constant input. The vibrations may grow in amplitude (become unstable) and occurs near the natural frequency of the system regardless of the input. |
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Term
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Definition
| where the cutting edge and the cutting motion are not perpendicular to each other. |
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Term
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Definition
| The onset of the shear process takes place along the lower boundary of the shear zone defined by this? |
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Term
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Definition
| can be found by using sophisticated electronics and slow-motion playback. |
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Term
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Definition
| Also known as shear. A deformation of a solid body in which a plane in the body is displaced parallel to itself relative to parallel planes in the body; quantitatively, it is the displacement of any plane relative to a second plane, divided by the perpendicular distance between planes. The force causing such deformation. |
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Term
| Shear force (flow stress) |
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Definition
| External force that acts parallel to a plane, unlike compressive force and tensile force which act perpendicularly. |
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Term
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Definition
| also known as the unit horese power (hp/lb/hr) |
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Term
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Definition
| the ____ of an object is the magnitude of its velocity (the rate of change of its position); it is thus a scalar quantity. |
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Term
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Definition
| A stability lobe diagram is a plot that separates unstable combinations of chip width, or axial depth of cut in peripheral end milling, and spindle speed (i.e., those that produce chatter) from stable combinations. |
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Term
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Definition
| Shaping a member on a lathe. |
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Term
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Definition
| A continuing periodic change in a displacement with respect to a fixed reference. This is the mechanism by which a process dissipates energy. Also called chatter. |
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Term
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Definition
| A device used to locate and hold a workpiece. The workholding device references the tool performing the operation on the part being held. |
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Term
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Definition
| An object being worked on with a tool or machine. |
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