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Define non destructive testing and discuss non mechanical properties

Hi
can you help me with sections 2,3 of a materials assignment?
section 2
Define what is non destructive testing and illustrate some of it's usage. to support this detail three methods of non destructive testing and write a clear explanation of the process involved and where they might be used.
section 3
choose one of the following areas and outline some of the properties which can be defined and how these apply to metals, polymers and ceramics. within the context of this section define examples of materials which exhibit good properties and which exhibit poor properties.
-electric properties
-magnetic properties
-thermal properties
-optical properties
use a wide range as possible of research material. sources used should be clearly outlined in a bibliography at the end of the report.

cheers mark

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Section 2:

Nondestructive testing is the examination of an object or material with technology that does not affect the object's future usefulness. The material of the test object is virtually undamaged, or damaged only very slightly, thereby ensuring that the object can be put in use for the original purpose it was constructed or manufactured for. NDT is typically useful when the object to be tested is exorbitantly costly and destroying it for testing purposes would be a severe strain on the manufacturer’s exchequer. NDT can also be put in use for determining flaws and cracks developed due to wear and tear in already existing and working structures. For example, a bridge or a dam built and in use for decades now can be tested for fractures and cracks developed during operations using NDT, thereby prompting repair and maintenance, and helping in preventing catastrophic damage. However, carrying and setting up NDT equipment in the field might pose a major challenge. Following are three methods of NDT employed in industry and research worldwide:
1. Ultrasonic Testing: Ultrasonic inspection uses sound waves of short wavelengths and high frequency to detect flaws or measure material thickness. It is used as an alternative inspection method to radiography to locate sub-surface flaws in all industry sectors. Usually, pulsed beams of high frequency ultrasound are used via a hand held transducer placed on the specimen. Any sound from the pulse that is reflected and returns to the transducer (like an echo) is shown on a screen, which gives the amplitude of the pulse and the time taken to return to the transducer. Flaws anywhere through the specimen thickness reflect the sound back to the transducer. Flaw size, distance and reflectivity can be interpreted. Automated systems are used for testing in a production environment and for some special applications.
2. X-Ray Radiography: Radiography principle relies on penetrating radiation like X-Rays generated by a source, more or less absorbed in the test-piece to be ...

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