Term
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Definition
| involves listening for indications of failure. Temporary monitoring can be used to detect the formation of cracks in materials during production operations, such as welding and subsequent cooling of the weld region. Almost all materials will emit high-frequency sound when stressed, deformed, or undergoing structural changes, such as the formation or growth of a crack or defect. (pg. 242) |
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Term
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Definition
| another computer reconstruction technique, this time based on ultrasound reflections from within the part. (pg. 243) |
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Term
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Definition
| an inspection technique that provides a cross-sectional view of the interior of an object along a plane parallel to the X-ray beam. (pg. 243) |
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Term
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Definition
| links the transducer to the piece to be inspected and transmits the vibrations into the part because air is a poor transmitter of ultrasonic waves; generally a liquid such as oil or water (page 237) |
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Term
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Definition
| a flaw that is clearly unacceptable and a cause for rejection (page 244) |
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Definition
| a means of product assessment that evaluates product quality and ensures the absence of any performance-impairing flaws; components or assemblies are selected and then subjected to conditions that induce failure (page 232) |
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Term
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Definition
| A sufficiently small flaw that does not affect a material throughout its useful lifetime, never changing size or shape (pg. 244). |
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Term
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Definition
| When an electrically conductive material is brought near an alternating-current coil that produces an alternating magnetic field, surface currents (eddy currents) are generated in the material. Cracks, voids, inclusions, and seams can affect the magnitude and direction of the induced eddy currents and can be detected by the electronics (pg. 241). |
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Definition
| (Pg. 243) A function of a material’s chemistry, processing history, and structural soundness; used for alloy identification, flaw detection, or the assurance of proper processing |
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Term
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Definition
| (Pg. 244) Flaw-free is an unreasonable expectation for any material. This sed to be the standard for materials, but now that there are better detection methods this is not possible. |
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Term
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Definition
| (Pg. 232) used to provide insight on the quality of a product. |
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Term
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Definition
| A measure of the impediment to the flow of alternating current, measured in ohms at a given frequency. Larger numbers mean higher resistance to current flow. (pg 240) |
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Term
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Definition
| a form of nondestructive testing designed to determine the existence or absence of leak sites and the rate of material loss through the leaks (pg 242) |
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Term
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Definition
| ), an effective method of detecting surface defects in metals and other nonporous materials by applying a penetrant to the surface and allowing to dry (pg 234) |
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Term
| Magnetic Particle Inspection |
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Definition
| based on distorted magnetic fields created by flaws in a magnetized material. Magnetic particles are used to find these flaws in the test piece.(Page 235) |
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Term
Nondestructive Testing
(Nondestructive Inspection) |
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Definition
| examination of a product in a manner that retains its usefulness for future service (page 233) |
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Term
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Definition
| a standard test piece with known properties and dimensions that is often included in a radiographic exposure. It is made of similar material as the piece to be inspected and is used for comparison (page 240) |
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Term
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Definition
| a liquid material capable of wetting the entire surface and being drawn into fine openings |
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Term
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Definition
-a means of assuring product quality
-a product is subjected to a load or pressure of some determined magnitude |
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Term
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Definition
| -an ultrasonic pulse is introduced into the piece to be inspected and the echoes from opposing surfaces and any intervening flaws are detected by the receiver |
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Term
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Definition
| a shadow pattern is created when certain types of radiation (X-ray, gamma rays, or neutron beams) penetrate an object and are differentially absorbed due to variations in thickness, density, or chemistry, or the presense of defects in the specimen |
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Term
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Definition
| can be used to determine the thickness of a plate or sheet from one side of the material. Input pulses of varying frequency are fed into the material. When resonance is detected by an increase in energy at the transducer, the thickness can be calculated from the speed of sound in the material and the time of transverse |
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Term
| Through Transmission Technique |
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Definition
| requires separate sending and receiving transducers. A pulse is emitted by the sending transducer and detected by a receiver on the opposite surface. Flaws in the material decrease the amplitude of the transmitted signal because of back-reflection and scattering |
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Term
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Definition
| refers to the ability to hit what is aimed at (246) |
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Term
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Definition
| are used to monitor the output of a process by sampling, by measuring selected quality characteristics, by plotting the sample data on the chart and then by making decisions about the performance of the process. They are widely used as aids in maintaining quality and detecting trends in quality before defective part are produced.(261) |
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Term
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Definition
| (pg. 255, 264)- One of the most effective methods for improving quality is the cause and effect diagram because of its structure. It was initially developed by Kaorw Ishikowa in 1943 , this diagram organizes theories about the probable cause of a problem. A fishbone diagram can be used in conjunction with the control chart to root out the causes of problems |
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Term
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Definition
| a histogram is a representation of a frequency distribution that uses rectangles whose widths represent class intervals and whose heights are proportional to the corresponding frequencies. Pg 250 |
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Term
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Definition
| A histogram can explain how the natural tolerance limits of the distribution can be compared with the engineering specifications to determine if the process is centered at the nominal value. Pg 260 |
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Term
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Definition
| is normally distributed, that is, has the classic bell shaped distribution in which percentages are dictated by the number of standard deviation from the central value or the mean. Pg 254 |
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Term
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Definition
| One of the four alternatives when the process is not capable of meeting the design specifications. Determine whether the precision of the process can be improved by numerous tasks, such as switching cutting tools, overhauling the existing process, and using a factorial procedure |
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Term
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Definition
| the ability to consistently hit the bull’s-eye you are aiming at. To measure it, the target is inspected after you have finished shooting. So the capability of manufacturing processes is determined by measuring the output of the process. |
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Term
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Definition
| the product is examined to determine whether or not the processing accomplished was what was specified by the designer in the design, usually the nominal size and the tolerance. |
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Term
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Definition
| a measure of variability (or spread) of a process. This is computed by subtracting the smallest observation value from the largest observation value. Can be estimated with a sample range—computed by ((sum of ranges)/ k). (Ch.12; p.249) |
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Term
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Definition
| an estimate of the true mean; computed to estimate the mean of the process. Computed by dividing the sum of all observations (xi) by the total number of observations, n. (Ch.12 p.249) |
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Term
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Definition
| Consists of both upper and lower limits (USL and LSL). Together, they form an interval in which all measured observations are accepted and considered close enough to the sample mean. Defines the outermost values of acceptance for the process. Can be viewed on a histogram or run chart. (Ch.12; p.248) |
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Term
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Definition
): variability of the individual measurements about the average, where σ = √∑ n i=1 (Xi- μ) 2 / (n)
page 261 |
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Term
| Statistical Process Control |
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Definition
): studying samples and deciding about the behavior of the whole parent population; is a common in industrial inspection operations and includes the techniques of the histogram and control charts
page 260 |
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Term
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Definition
| the drive toward superior quality control has led to the introduction of the Taguchi methods for improvement in products, product design, and processes; spans a much wider scopes of functions and includes the design aspects of products and processes in order to improve quality- see list of features on page 256-257 |
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Term
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Definition
| the inherent uniformity. This may have assignable causes and may be correctable if the cause can be found and eliminated. The variability that cannot be eliminated is said to be inherent. With perfect accuracy, no variability. (p. 247) |
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Term
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Definition
| an inspection technique that provides a cross-sectional view of the interior of an object along a plane parallel to the X-Ray beam. Pg 243 |
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Term
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Definition
| a device that transforms electrical energy into mechanical vibrations. Pg 237 |
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Term
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Definition
| involves sending high frequency waves through a material and observing the response. Pg 237 |
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Term
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Definition
| is probably the most simple and most used nondestructive testing method. Optical aids, such as microscopes and/or video cameras can be used to expand capabilities. This method is limited to detection of surface flaws; The skill of the inspector is very important; should be the primary means of inspection. (pg. 234) |
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Term
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Definition
| the modifications that are incorporated into a pattern. Pg(288) |
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Term
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Definition
| if the riser is contained entirely within the mold. Pg(287) |
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Term
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Definition
| this process exploits the fluidity of a liquid as it flows, assumes the shape of a prepared container, and solidifies upon cooling. Pg(276) |
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Term
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Definition
| speeding the solidification of the casting. Pg(288) |
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Term
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Definition
| a narrow band of randomly oriented crystals that forms on the surface of a casting. Pg(282) |
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Term
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Definition
| smallest cross-sectional area, serves to control the rate of metal flow. Pg(285) |
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Term
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Definition
| total solidification time, t, is the time from pouring to the completion of solidification; V is the volume of the casting; A is the surface area; and B is the mold constant. t = B(V / A)^n pg(282) |
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Term
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Definition
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Term
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Definition
| in the cast structure, the long, thin columnar grains that are produced by the favorably oriented crystals that continue to grow (pg. 282) |
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Term
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Definition
| provide one of the most useful tools for studying the solidification process; discussed in chapter 4 (pg. 280) |
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Term
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Definition
| rate at which the liquid or solid is cooling; can be viewed as the slope of the cooling curve at any given point (pg. 281) |
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Term
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Definition
| in a horizontally-parted two-part mold, the name that is given to the top half of the pattern, flask, mold, or core (pg. 278) |
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Term
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Definition
| a sand (or metal) shape that is inserted into a mold to produce the internal features of a casting, such as holes or passages for water cooling (pg. 278) |
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Term
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Definition
| the mold or die used to produce casting cores (pg. 279) |
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Term
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Definition
– a region that is added to the pattern, core, or mold and is used to locate and support the core within the mold (pg. 279)
– (in the casting process) a region that is added to the pattern, core, or mold and is used to locate and support the core within the mold (pg. 279). |
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Term
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Definition
| – a riser (see riser) which fills with metal that has already flowed through the mold cavity (pg. 287). |
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Term
| Directional Solidification |
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Definition
| Solidification process in which the solidification interface sweeps continuously through the material; can also be used to assure the production of a sound casting (pg.280). |
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Term
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Definition
| The taper on a pattern or casting that permits it (the casting) to be withdrawn from the mold (pg. 279). |
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Term
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Definition
| The bottom half of any of the casting mold and features (pg. 278). |
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Term
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Definition
| material that can become trapped in the casting and impair surface finish, machinability, and mechanical properties (pg. 283). |
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Term
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Definition
| – when new crystals nucleate in the interior of the casting and then grow to produce another region on spherical, randomly-oriented crystals, this is known as equiaxed zone |
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Term
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Definition
| (pg 288) – the casting process for which a new mold must be created for each casting. |
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Term
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Definition
| (pg 288) – masses of high-heat-capacity, high-thermal-conductivity material that are placed in the mold adjacent to the casting to accelerate the cooling of various regions |
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Term
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Definition
| pg 278) – the rigid metal or wood frame that holds the molding aggregate |
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Term
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Definition
| (pg 284) – the ability of a metal to flow and fill a mold; affects the minimum section thickness that can be cast, the maximum length of a thin section, the fineness of detail, and the accuracy of filling mold extremities |
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Term
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Definition
| (pg 281) – the difference between the liquidus and the solidus temperatures |
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Term
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Definition
| (pg 284) – passing small bubbles of inert or reactive gas through the melt |
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Term
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Definition
| (pg 283): Liquid metals contain significant amounts of dissolved gas, and after solidification, the solid structure cannot accommodate the gas and the rejected atoms tend to form bubbles within the casting |
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Term
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Definition
| (pg 279): a controlled entrance which molten metal passes through during the casting system |
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Term
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Definition
| (pg 279) the network of connected channels used to deliver the molten metal to the mold cavity |
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Term
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Definition
| (pg 280) a set of techniques used in metallurgy to ensure that the crystallites (grains) that make up a metallic object are sufficiently small |
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Term
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Definition
| (pg 280) An increase in metals crystal size as annealing temperature is raised. Growth occurs by invasion of crystal arears by other crystals. |
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Term
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Definition
| (pg 292) Localized thick sections of metal that cool more slowly than the other sections which tend to be the sites of localized abnormal shrinkage |
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Term
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Definition
| ) Intentionally introducing impurities into the liquid before pouring into mote formation of a uniform, fine-grained product |
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Term
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Definition
| Pieces of metal that are placed within the mold cavity to absorb heat and promote more rapid solidification. They melt during the operation and become part of the final piece so they should be made from the same alloy as is being cast. (page 288) |
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Term
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Definition
| temperature at which all of the material is liquid (page 281) |
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Term
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Definition
| receive the last hot metal that enters the mold and generally do so at a time when the metal in the mold cavity has already begun to solidify. (page 287) |
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Term
| Local Solidification Time |
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Definition
| The time from the start of solidification to the end of solidification. (page 281) |
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Term
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Definition
| material that must be included into the design for a casting to be machined. (page 290) |
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Term
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Definition
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Term
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Definition
| the part of the mold that the fluid metal flows into. It must have all of the features desired of the cast piece. (page 278) |
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Term
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Definition
-‘B’ in Chvorinov’s rule
-incorporates the characteristics of the metal being cast |
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Term
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Definition
| -in a casting procedure, the material that is packed around the pattern before the pattern is removed |
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Term
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Definition
-made of metal or graphite
-use is generally restricted to products where large quantities are desired |
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Term
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Definition
-occurs when a stable particle of solid forms from with in the molten liquid
-generally occurs at a temperature below the equilibrium melting point |
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Term
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Definition
| -a riser that is open to the atmosphere |
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Term
Parting Line
(Parting Surface) |
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Definition
| -the surface where one section of the mold mates with the other section or sections |
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Term
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Definition
| -a duplicate of the part to be cast, modified dimensionally to reflect both the casting process and the material being cast. |
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Term
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Definition
| -a defect where the metal not only fills the mold cavity but also fills the small voids between the particles of a sand mold |
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Term
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Definition
| the portion of the gating system that initially receives the molten metal from the pouring vessel and controls the delivery to the rest of the mold |
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Term
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Definition
| the temperature of the liquid metal when it first enters the mold cavity |
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Term
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Definition
| when undercooling is required to induce the initial nucleation, the subsequent solidification may release enough heat to cause an increase in temperature back to the melting point, known as _______ |
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Term
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Definition
| an extra void created in the mold that will also fill with molten metal |
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Term
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Definition
| horizontal channels that the metal travels down after leaving the pouring cup |
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Term
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Definition
| – used to catch and trap metal and keep it from eintering the mold cavity |
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Term
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Definition
| measuring devices that are larger than a standard rule by the appropriate shrink allowance |
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Term
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Definition
| A volumetric contraction defined in 3 categories of shrinkage: shrinkage of the liquid, solidification shrinkages, and solid metal contraction (285). |
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Term
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Definition
| are located adjacent to the mold cavity and displaced horizontally along the parting line. SEE FIG. 13-10 (287). |
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Term
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Definition
| an economically feasible solution for molding productions of smaller quantities (278). |
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Term
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Definition
| referred to the oxygen that is associated in molten metal that can lead to major |
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Term
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Definition
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Term
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Definition
| shrinkage that occurs when a liquid turns into a solid (281) |
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Term
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Definition
| the solid form of a material on a cooling curve (285) |
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Term
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Definition
| Molten metal comes from the pouring cup into this vertical portion of a gating system; used to transfer the molten metal to the cast (pg. 279). |
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Term
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Definition
| used to dissipate the kinetic energy of the falling stream from the sprue (285) |
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Term
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Definition
| A material used in castings to provide protection against stress fractures (There was no definition really, this is a guess! 292) |
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Term
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Definition
| sits on top of a casting and serves as a reservoir for molten metal. The metal in this area will fill in any cracks or space due to shrinkage in the solidifying of the metal.(287) |
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Term
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Definition
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Term
| Total Solidification Time |
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Definition
| the time from the start of pouring to the end of solidification |
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Term
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Definition
| Tends to promote absorption of gases, oxidation of the metal, and erosion of the mold |
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Term
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Definition
| The difference between the melting point and the actual temperature of nucleation |
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Term
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Definition
| Sprays the molten metal through a low-pressure environment and under these conditions the amount of dissolved gas is reduced as the material seeks to establish equilibrium with its new surroundings |
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Term
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Definition
| Additional channels that may be included in a mold or core to provide an escape for the gases that are originally present in the mold or generated during the pour |
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Definition
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