Page 29 - 4711

of differential equations, displacement or acceleration at different points of the structure,
output is recorded and compared, an inadequate control system, have a known response to
certain radiographic inputs, measuring and interpreting the response to the radiographic input,
based on a particular scientific principle, subdivided into various techniques.
Make up and write down10 sentences using at least 10 word combinations given above .

Task II. Read the text and translate it into Ukrainian:

Methods of Nondestructive testing (NDT)
NDT methods may rely upon use of electromagnetic radiation, sound, and inherent
properties of materials to examine samples. This includes some kinds of microscopy to
examine external surfaces in detail, although sample preparation techniques for metalography,
optical microscopy and electron microscopy are generally destructive as the surfaces must be
made smooth through polishing or the sample must be electron transparent in thickness. The
inside of a sample can be examined with penetrating electromagnetic radiation, such as X -
rays or 3D X rays for volumetric inspection. Sound waves are utilized in the case of ultrasonic
testing. Contrast between a defect and the bulk of the sample may be enhanced for visual
examination by the unaided eye by using liquids to penetrate fatigue cracks. One method
(liquid penetrant testing) involves using dyes, fluorescent or non-fluorescing, in fluids for
non-magnetic materials, usually metals. Another commonly used method for magnetic
materials involves using a liquid suspension of fine iron particles applied to a part while it is
in an externally applied magnetic field (magnetic-particle testing). Thermoelectric effect (or
use of the Seeback effect) uses thermal properties of an alloy to quickly and easily
characterize many alloys. The chemical test, or chemical spot test method, utilizes application
of sensitive chemicals that can indicate the presence of individual alloying elements.
Electrochemical methods, such as electrochemical fatigue crack sensors, utilize the tendency
of metal structural material to oxidize readily in order to detect progressive damage.
Nondestructive testing or Non-destructive testing (NDT) is a wide group of analysis
techniques used in science and industry to evaluate the properties of a material, component or
system without causing damage. The terms Nondestructive examination (NDE),
Nondestructive inspection (NDI), and Nondestructive evaluation (NDE) are also commonly
used to describe this technology. Because NDT does not permanently alter the article being
inspected, it is a highly valuable technique that can save both money and time in product
evaluation, troubleshooting, and research. Common NDT methods include ultrasonic,
magnetic-particle, liquid penetrant, radiographic, remote visual inspection (RVI), eddy-
current testing, and low coherence interferometry. NDT is a commonly used in forensic
engineering, Metallurgical And Materials Engineering, mechanical engineering, electrical
engineering, civil engineering, systems engineering, aeronautical engineering, medicine, and
art.

Applications
Weld verification
1. Section of material with a surface-breaking crack that is not visible to the naked eye.
2. Penetrant is applied to the surface.
3. Excess penetrant is removed.
4. Developer is applied, rendering the crack visible.
In manufacturing, welds are commonly used to join two or more metal parts. Because
these connections may encounter loads and fatigue during product lifetime, there is a chance
that they may fail if not created to proper specification. For example, the base metal must
reach a certain temperature during the welding process, must cool at a specific rate, and must

28