Term
| • Acoustic emission (p. 242)— |
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Definition
| involves listening for indications of failure because almost all materials emit high frequency sounds when stressed |
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Term
| • Acoustic holography (p. 243)— |
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Definition
| computer reconstruction technique, that is time based on ultrasound reflections from within the part. |
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Term
| • Computed tomography (p. 243)— |
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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. |
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Term
| • Coupling medium (p. 237)— |
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Definition
| in ultrasonic inspection, because air is a poor transmitter of ultrasonic waves, this is required to link the transducer to the piece to be inspected and transmit the vibrations into the part; generally a liquid such as oil or water; |
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Term
| • Critical flaw (p. 244)— |
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Definition
| larger defects, or defects of a more undesirable geometry that may grow or propagate under the same conditions of loading, often causing sudden or catastrophic failure. |
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Term
| • Destructive testing (p. 232)— |
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Definition
| a product assessment where components or assemblies are selected and then subjected to conditions that induce failure. |
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Term
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Definition
| an allowable flaw that is sufficiently small and will remain the same size and shape throughout its lifetime. |
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Term
| • Eddy-current testing (p. 241)— |
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Definition
| can be used to detect surface and near-surface flaws, such as cracks, voids, inclusions, and seams. When an electrically conductive material is brought near an alternating-current coil that produced an alternating magnetic field, surface currents (eddy currents) are generated in the material. These surface currents generate their own magnetic field, which interacts with the original, modifying the impedance of the originating coil. Various material properties and/or defects can affect the magnitude and direction of the induced eddy currents and can be detected by electronics. |
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Term
| • Electrical resistivity (p.243)— |
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Definition
| is a function of a material’s chemistry, processing history, and structural soundness. Measurement of resistivity can therefore be used to alloy identification, flaw detection, or the assurances of proper processing |
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Term
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Definition
| There was a time when the detection of a flaw was considered to be sufficient cause for rejecting a material or component, and material specifications often contained the term flaw-free. Such a criterion, however, is no longer practical because the sensitivity of detection methods has increased dramatically. |
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Term
| • Hardness testing (p. 232)— |
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Definition
| can be used to provide insight into the quality of a product; With the correct material and proper heat treatment, the resulting hardness values should fall within a well-defined range of values. Abnormal results usually indicate some form of manufacturing error, such as improprer material, missed operations or poorly controlled processes. Hardness tests can be performed quickly, and the surface indentations are often small enough that they can be concealed or easily removed from a product. |
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Term
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Definition
| a change in the magnetic field causes a change in the impedance of the coil, which in turn changes the magnitude of the current flowing through it; the ratio of the voltage phasor to the electric current phasor, a measure of opposition to time-varying electric current in an electric circuit |
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Term
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Definition
| a form of nondestructive testing designed to determine the existence of absence of leak sites and the rate of material loss through the leaks |
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Term
| • Liquid penetrant testing (p. 234)— |
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Definition
| also called dye penetrant inspection; an effective method of detecting surface defects in metals and other nonporous materials. |
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Term
| • Magnetic particle inspection (p. 235)— |
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Definition
| based on the principle that ferromagnetic materials (such as the alloys of iron, nickel, and cobalt), when magnetized, will have distorted magnetic fields in the vicinity of material defects. |
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Term
| • Nondestructive testing (aka nondestructive inspection) (P. 232)— |
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Definition
| the product is examined in a manner that retains its usefulness for future services. Tests can be performed on parts during or after manufacture, or even on parts that are already in service. |
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Term
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Definition
| a standard test piece used that is often included in a radiographic exposure; made of the same or similar material as the specimen and contain features with known dimensions. |
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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; used in liquid penetrant inspecting |
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Term
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Definition
| a means of assuring product quality where a product is subjected to a load or pressure of some determined magnitude (generally equal to or greater than the designer capacity or the condition expected during operation). |
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Term
| • Pulse-echo method (p. 238)— |
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Definition
| an ultrasonic pulse is introduced into the piece to be inspected, and the echoes from opposing surfaced and any intervening flaws are detected by a receiver. |
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Term
| • Radiographic Inspection (p238)- |
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Definition
| a shadow pattern is created when certain types of radiation penetrate an object and are differentially absorbed due to variations in thickness, density, or chemistry, or the presence of defects in a specimen. The transmitted radiation is permanently registered on photographic film. |
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Term
| • Resonance Testing (p238)- |
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Definition
| used to determine the thickness of a plate or sheet from one side of the material using ultrasonic waves. Input pulses of varying frequencies are fed into the material. Thickness is detected by the speed of sound and time of transverse.used to determine the thickness of a plate or sheet from one side of the material using ultrasonic waves. Input pulses of varying frequencies are fed into the material. Thickness is detected by the speed of sound and time of transverse. |
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Term
| • Through Transmission Technique (p238)- |
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Definition
| a technique of ultrasonic inspection in which a pulse is emitted by a sending transducer and is detected by a receiver transducer on the opposite surface. Flaws in the material decrease amplitude of the transmitted signal because of back-reflection and scattering. |
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Term
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Definition
| (not in book) imaging by sections or sectioning, through the use of any kind of penetrating wave. |
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Term
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Definition
| a device that transforms electrical energy into mechanical vibrations. It is used in Ultrasonic Inspection. |
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Term
| • Ultrasonic Inspection (p237)- |
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Definition
| involves sending high-frequency waves through a material and observing the response. Within the specimen, sound waves can be affected by voids, impurities, changes in density, delamations, and other imperfections. |
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Term
| • Visual Inspection (p234)- |
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Definition
| the simplest and most widely used nondestructive testing method in which a person is trained to visually look for defects. Sometimes mirrors, magnifying glasses, and microscopes are used. |
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Term
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Definition
| aim; the ability to hit the target or reach a goal. |
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