1. Material Science & Metallurgy (2131904)
B.E. MECH – Sem III rd
Prepared by,
PATEL SHREY B. (170953119031)
GROUP : B2 - DD 42
Guided by,
SUSHIL CHAURASIA (Mech Deptt.)
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2. Content :-
• Definition
• Common Characteristics
• Importance
• Areas of Application
• Advantage
• Application
• Difference between Destructive Test & Non-Destructive Test
• Common NDT Method
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3. What is NDT ???
• Nondestructive testing (NDT) is the process of inspecting, testing, or
evaluating materials, components or assemblies for discontinuities, or
differences in characteristics without destroying the serviceability of
the part or system. In other words, when the inspection or test is
completed the part can still be used.
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4. Common Characteristics :-
• The application of testing medium to product to be tested.
• The changes in testing medium due to defects in structure of product.
• A means by which it detects these changes.
• Interpretation of these changes to obtain information about the flaws in
structure of product.
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5. Importance of NDT :-
• Does not permanently alter the article being inspected
• Save both money and time in product evaluation, troubleshooting and
research
• Can be used to detect flaws in an in-process machine part
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6. Advantage of NDT :-
• Less Waste. Since substances are not altered by NDT, they can
continue to be used. That means less wasted samples.
• Less Downtime. Using some methods, the materials can be tested
even while in use, which eliminates the need to shut down operations
during testing.
• Accident Prevention. Non-Destructive Testing can help prevent
accidents, which helps reduce costs associated with repairs,
replacement, and equipment loss and business shut down.
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7. • Comprehensive Testing. Since this type of testing does not alter
substances, every component or product can be tested. There is no
need for selective sampling, which tests only a portion of the
components. NDT techniques can also be applied at multiple stages of
development and construction, allowing manufacturers to identify and
repair or replace problem pieces before construction is complete, as
well as after the product has been put to use.
• Increased Product Reliability. Advanced and more comprehensive
testing ensures better products. Problems can be identified and fixed
before the product goes to market, and products that are already in use
can be tested more frequently to ensure they continue to perform as
expected.
• Identify Areas of Concern Before Failure. Components that fail can
be costly to repair or replace and may lead to an unexpected shutdown
of the business or in some cases, disasters. NDT can identify these
areas of concern before they become a problem.
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8. Areas of Application :-
Non-Destructive Testing is used every day in industries all around us,
ensuring our safety and security. NDT methods are used:
• In product evaluation.
• For troubleshooting
• For identifying areas of wear
• For assuring the safety and reliability of structures and component
• To find flaws or irregularities both on and under the surface of
materials.
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9. NDT is used in many industries, including:
• Engineering
• Air
• Space
• Rail
• Motor vehicles
• Utilities
• Power and energy companies
• Construction
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10. Various NDT Method :-
• NDT methods rely upon use of electromagnetic radiation, sound,
inherent properties of materials (such as thermal, chemical, magnetic
etc.) to examine samples.
• Some of the methods :
Ultrasonic Testing
Magnetic particle inspection
Dye penetrant inspection/Liquid penetrant inspection
Radiographic testing
Eddy-current testing
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11. Ultrasonic Testing :-
• Very short ultrasonic pulse-waves are launched into materials to detect
internal flaws.
• Used for steel and other metals and alloys, can also be used on
concrete, wood and composites (with lessresolution).
• Used in many industries including aerospace, automotive and other
transportation sectors.
• Two methods of receiving the ultrasound waveform:
- Reflection
- Through Transmission
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12. • Part is magnetized.
• Presence of a surface or subsurface discontinuity in the material allows
the magnetic flux to leak, since air cannot support as much magnetic
field per unit volume as metals.
• Ferrous iron particles are then applied to the part.
• Particles will build up at the area of leakage and form whatis known as
an indication.
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Magnetic Particle Testing :-
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13. • Penetrant may be applied to the test component by dipping, spraying, or
brushing
• After adequate penetration time, the excess penetrant is removed, a
developer is applied.
• Developer helps to draw penetrant out of the flaw where an invisible
indication becomes visible to the inspector.
• Procedure :-
(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.
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Dye Penetration Testing :-
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15. Radiographic Testing :-
• Short wavelength
electromagnetic radiation (high
energy photons) to penetrate
various materials.
• The amount of radiation
emerging from the opposite side
of the material can be detected
and measured
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16. • Uses electromagnetic induction to detect flaws in conductive materials.
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Eddy Current Testing :-
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17. • Variations in the phase and magnitude of these eddy V currents can be
monitored using a second 'receiver' coil, or by measuring changes to
the current flowing in the primary 'excitation' coil.
• Variations in the electrical conductivity or magnetic permeability of
the test object, or the presence of any flaws, will cause a change in
eddy current and corresponding change in the phase and amplitude of
the measured current.
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